Digitized  by  the  Internet  Archive 

in  2011  with  funding  from 

LYRASIS  members  and  Sloan  Foundation 


http://www.archive.org/details/neworunusualplanOOclin 


Connecticut    Agricultural 


NEW  HAVEN,   CONN. 
Bulletin  222  August,   1920 


NEW  OH  UNUSUAL 

PLANT  INJURIES  AND  DISEASES 
Found  in  Connecticut,   1916-1919 

By 
George  P.    Clinton,    Sc.D.,   Botanist 


CONTENTS 

page 

Introduction ... .. 397 

Dry  Rot  Fungus  destroying  House  Timbers 398 

Fungi  of  Moldy  Unsalted  Butter 400 

Injuries  and  Diseases  of  Plants 404 


The  Bulletins  of  this  Station  are  mailed  free  to  citizens  of  Connecti- 
cut who  apply  for  them,  and  to  others  as  far  as  the  editions  permit- 


CONNECTICUT  AGRICULTURAL  EXPERIMENT  STATION. 

OFFICERS  AND  STAFF 
August,  1920. 


BOARD  OF  CONTROL. 
His  Excellency,  Marcus  H.  Holcomb,  ex-officio,  President. 

James  H.  Webb,  Vice  President Hamden 

George   A.    Hopson,   Secretary New  Haven 

E.  H.  Jenkins,  Director  and  Treasurer New  Haven 

Joseph  W.  Alsop Avon 

Charles  R.  Treat Orange 

Elij  ah  Rogers  Southington 

William  H.  Hall South  Willington 


Administration. 


Chemistry. 

Analytical  Laboratory. 


STAFF. 

E.  H.  Jenkins,  Ph.D.,  Director  and   Treasurer. 
Miss  V.  E.  Cole,  Librarian  and  Stenographer. 
Miss  L.  M.  Brautlecht,  Bookkeeper  and  Stenographer. 
William  Veitch,  In  charge  of  Buildings  and  Grounds. 


Protein  Research. 
Botany. 


Assistant  Chemists. 


E.  Monroe  Bailey,  Ph.D.,  Chemist  in  Charge. 

R.  E.  Andrew,  M.A.,  C.  E.  Shepard, 

H.  D.  Edmond,  B.S.,  Owen  Nolan. 

Frank  Sheldon,  Laboratory  Assistant. 

V.  L.  Churchill,  Sampling  Agent. 

Miss  A.  H.  Moss,  Clerk. 

T.  B.  Osborne,  Ph.D.,  D.Sc,  Chemist  in  Charge. 

G.  P.  Clinton,  Sc.D.,  Botanist. 

E.  M.  Stoddard,  B.S.,  Assistant  Botanist. 

Miss  Florence  A.  McCormick,  Ph.D.,  Scientific  Assistant. 

G.  E.  Graham,  General  Assistant. 

Mrs.  W.  W.  Kelsey,  Stenographer. 


Entomology. 


Plant  Breeding. 
Vegetable  Growing. 


W.  E.   Britton,  Ph.D.,  Entomologist:    State  Entomologist. 
B.  H.  Walden,  B.Agr.,  I.  W.  Davis,  B.Sc,  i  Assistant 
M.  P.  Zappe,  B.S.,  Philip  Garman,  Ph.D.     j     Entomologists. 
Miss  Gladys  M.  Finley,  Stenographer. 

Walter  O.  Filley,  Forester,  also  State  Forester 

and  State  Forest  Fire  Warden. 
A.  E.  Moss,  M.F.,  Assistant  State  and  Station  Forester. 
H.  W.  Hicock,  M.F.,  Assistant. 
Miss  Pauline  A.   Merchant,   Stenographer. 

Donald  F.  Jones,  S.D.,  Plant  Breeder. 
C  D.  Hubbell,  Assistant. 


REPORT  OF  THE  BOTANIST, 

G.  P.  Clinton, 

for  1919. 

NEW  OR  UNUSUAL  PLANT  INJURIES  AND  DISEASES, 
FOUND  IN  CONNECTICUT,  1916-1919. 

Introduction. 

In  our  first  Report,  for  1903,  we  gave  brief  mention  of  all  of 
the  Connecticut  plant  troubles,  not  including  insect  injuries,  that 
had  been  reported  by  others  or  observed  by  ourselves  up  to 
that  time.  Since  then  in  most  of  our  Reports,  additional  troubles 
have  been  recorded  in  the  same  manner.  However  since  191 5, 
no  account,  in  this  general  way,  has  been  rendered  of  the  troubles 
that  have  come  to  hand  during  these  four  years.  It  is  the  aim 
of  the  present  Report  to  cover  this  period,  reporting  such  of 
these  as  have  been  definitely  determined. 

As  in  previous  Reports  we  discuss  both  diseases  and  injuries, 
including  abnormal  or  monstrous  growths,  of  all  our  economic 
plants.  Most  of  these  troubles  rare  caused  by  fungi  and  they 
are  indicated  here  by  the  common  name  in  small  caps  with  the 
scientific  name,  where  definitely  known,  in  italics.  The  other 
troubles  follow  these  and  are  indicated  by  a  common  name 
printed  in  italics.  As  practically  all  of  these  latter  are  mechani- 
cal, environmental  or  so-called  physiological  diseases  or  injuries, 
they  have  no  scientific  name.  As  in  the  past  these  troubles  are 
most  conveniently  reported  in  alphabetical  order  under  their 
hosts,  also  arranged  alphabetically  according  to  their  common 
names  with  scientific  names  following. 

We  shall  not  attempt  here  to  give  in  any  detail,  as  previously, 
the  weather  conditions  of  each^  year  and  their  bearing  on  the 
suppression  or  development  of  these  troubles.  It  might  be  well 
to  note  in  passing  that  the  winter  of  1917-1918  was  one  of  the 
most  severe  winters  since  we  began  our  disease  survey  of  Con- 
necticut, and  that  there  resulted  great  injury  to  perennial  plants, 
especially  to  cultivated  fruit  trees.  The  injury  to  the  wood  and 
flower   buds   of   peach   trees   from   this   and   the  preceding   and 


398         CONNECTICUT    EXPERIMENT   STATION   BULLETIN   222. 

following  winters  has  been  such  as  to  put  this  prominent  fruit 
industry  largely  out  of  business.  The  spring  and  early  summer 
of  19 1 8  were  SO'  wet  and  the  midsummer  so  dry  that  very  unusual 
troubles  of  potatoes,  largely  physiological,  developed.  Further- 
more the  spring  and  summer  of  1919  had  so  much  rainy  or 
muggy  weather  that  an  unusually  large  number  of  fungous 
diseases  developed,  including  very  serious  injury  by  the  late 
potato  blight.  The  lack  of  potash  in  most  fertilizers,  due  to 
the  war  during  these  years,  also  played  some  part  in  the  develop- 
ment of  unusual  troubles,  especially  of  potato  and  tobacco. 


Before  proceeding  to  a  specific  account  of  these  various 
troubles,  we  wish  to  briefly  discuss  here  two  that  do  not  come 
strictly  under  the  designation  of  "plant  diseases,"  since  while 
of  a  fungous  nature  their  injurious  activities  were  directed  to 
the  destruction  of  household  timbers  in  one  case,  and  household 
butter  in  the  other. 

DRY   ROT. 

Dry  Rot  Fungus,  Merulius  lacrymans  (Wulf.)  Schum.  We 
first  called  attention  to  this  fungus  in  our  Report  of  1906, 
pp.  336-41,  where  we  noted,  with  illustrations,  its  action  on 
the  wainscoting  of  a  church  basement  at  Stony  Creek.  Again, 
in  1916  (Rep.  1915:424-5.)  we  reported  a  vigorous  devel- 
opment of  the  fungus  on  flooring,  boxes,  tools  and  heads  of 
sewing  machines  at  the  Singer  Mfg.  Company's  Plant  in  Bridge- 
port. 

An  even  more  destructive  and  luxuriant  growth  of  the  fungus, 
than  at  either  of  these  places,  was  called  to  our  attention  in  July, 
1918,  by  Mrs.  Robert  H.  Comstock,  who  wrote  in  part  as  fol- 
lows :  "Five  years  ago  we  built  a  small  house  on  high  farm 
land  along  the  sandy  beach  of  the  Sound  at  Westbrook,  Conn. 
We  laid  a  cement  foundation  but  did  not  dig  a  cellar  and  when 
the  land  was  graded  the  cement  was  almost  entirely  covered,  as 
we  particularly  wanted  the  cottage  to  set  low.  For  several 
years  we  have  noticed  a  fungous  growth  on  the  partitions  and 
under  some  built-in  drawers  in  the  middle  of  the  house.  This 
spring  we  found  the  floor  was  rotted  out,  even  the  top  floor 
was  more  than  half  gone."     Plate  XXXIII,  a. 


DRY   ROT   FUNGUS.  '  399 

At  Mrs.  Comstock's  request  we  inspected  this  unoccupied 
shore  cottage,  a  view  of  which  is  given  here,  making  a  detailed 
examination  as  to  the  cause  and  the  amount  of  injury.  It 
was  readily  seen  that  the  trouble  was  due  to  the  dry-rot  fungus, 
Merulius  lacrymans,  as  it  was  found  in  good  fruiting  condition. 
In  fact  the  spores  from  the  fruiting  bodies  had  developed  so 
abundantly  that  they  had  settled  as  a  very  evident  reddish-brown 
dust  all  over  the  floors  and  tables  except  where  these  were  pro- 
tected by  covers  so  that  when  the  latter  were  raised  a  distinct 
boundary  showed  between  the  covered  and  uncovered  surfaces. 
The  cement  foundation  had  practically  no  openings  allowing  for 
ventilation,  thus  there  was  a  closed  air  space  of  about  a  foot  be- 
tween the  wood  beams  supporting  the  double  floor  and  the  ground. 
This  prevented  the  drying-out  of  the  air  and  gave  ideal  condi- 
tions for  the  development  of  the  fungus  when  once  it  got  started 
on  the  wood.  There  were  no  eave  troughs  to  carry  away  the 
water  from  the  roof  and  likewise  the  water  from  the  ice-box 
went  into  the  ground  under  the  house,  thus  increasing  the  damp- 
ness. 

Some  idea  of  the  destruction  of  the  woodwork  can  be  gained 
from  the  two  pictures  shown  here,  one  with  the  flooring  par- 
tially removed.  Some  of  the  wood  was  so  rotten  as  to  crumble 
easily  as  punk  between  the  fingers.  The  entire  floor  of  the 
living  room,  Plate  XXXIII,  b,  together  with  the  floor  joist,  had  to 
be  removed.  Considerable  injury  in  the  kitchen,  Plate  XXXIII,  c, 
under  a  built-in  set  of  drawers  and  in  an  adjacent  closet  also  was 
evident,  and  here  the  fungus  had  gone  up  between  the  walls  of 
the  board  partitions  a  short  distance.  There  was  no  evidence 
that  the  fungus  had  reached  the  second  story.  The  fungous 
growth  was  very  luxuriant  on  the  under  surface  of  the  floor 
boards  both  in  its  thick,  whitish,  felt-like  mycelium  and,  in  places, 
in  the  reddish-brown,  laxly-poroid,  fruiting  surfaces. 

The  remedial  measures  suggested  were  as  follows : — The  re- 
moval and  burning  of  all  infected  wood  and  rubbish;  the  creosot- 
ing,  if  possible,  of  the  new  wood  used;  the  building  of  several 
sunken  areaways,  protected  only  by  wire  netting,  to  allow  free 
access  of  air  under  the  house ;  the  placing  of  eaves  and  leaders 
and  a  drain  to  carry  away  the  water  from  the  roof  and  the  ice 
chest.     A  year  later  we  examined  the  cottage  and  found  that 


4-00  CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

most  of  these  suggestions  had  been  carried  out.  There  was  a 
very  good  air  drainage  under  the  house  by  five  sunken  openings, 
two  on  one  side  and  three  on  the  other,  and  part  of  the  earth 
had  been  removed  making  a  larger  air  space.  We  saw  no  indi- 
cations of  further  development  of  the  fungus.  Somewhat 
similar  suggestions  were  made  for  the  Stony  Creek  and  Bridge- 
port outbreaks.  We  have  had  no  complaints  of  further  trouble 
at  either  of  these  places,  and  so  judge  that  the  fungus  has  been 
kept  largely  if  not  entirely  in  check.  We  are  convinced  from 
our  experience  that  this  fungus  depends  in  great  measure  for  its 
development  upon  a  fairly  small  and  tightly  closed  air  space  next 
the  wood,  and  a  sufficient  amount  of  water  to  keep  the  air  therein 
constantly  saturated  or  at  least  above  the  normal  amount. 

MOLDY  UNSALTED  BUTTER. 

The  second  trouble,  see  Plate  XXXIV,  a,  that  of  moldy  unsalted 
butter,  was  really  first  called  to  our  attention  in  1913.  With  Mr. 
Stoddard  we  made  a  preliminary  investigation  of  the  trouble  then 
and  during  1914  and  1915,  intending  to  make  a  more  complete 
study  of  it  later,  but  as  no  complaints  have  come  in  since  we 
have  not  done  so.  We  make  this  short  report  here  as  a  matter 
of  record  as  little  has  been  published  by  botanists  in  this  coun- 
try about  the  trouble. 

The  first  sample  sent  us  was  received  in  the  late  fall  of  1913 
from  A.  L.  Kuran  of  the  New  Hartford  Creamery.  In  Janu- 
ary, 1914,  Prof.  H.  F.  Judkins  of  Storrs  sent  us  a  pound  package 
from  the  Suffield  Creamery  and  another  sample  from  a  different 
source  in  November.  In  these  and  most  other  samples'  seen 
of  wrapped  butter,  there  developed  on  the  surface  more  or 
less  numerous  small  spots  of  a  blackish  and  others  of  a  decided 
reddish  color.  These  were  easily  determined  as  due  to  fungous 
growths.  In  all  the  samples  seen  these  molds  did  not  penetrate 
very  deeply  into  the  butter.  One  of  the  specimens  which  we 
have  kept  ever  since  1915  in  a  closed  glass  jar,  now,  however, 
shows  the  whole  surface  overgrown  with  mixed  olive-black  and 
reddish  growths  and  the  interior  entirely  changed  into  a  some- 
what dried  red  substance  penetrated  by  mycelium.  Concerning 
the  Suffield  sample  Prof.  Judkins,  under  date  of  Jan.  7th,  wrote 
in  part  as  follows : — 


MOLDS    OF    BUTTER.  40I 

"I  am  sending  in  a  separate  package  a  pound  of  butter  which  I  obtained 
from  the  Suffield  creamery.  You  will  note  that  this  butter  is  unsalted  and 
it  is  a  rather  long  story  to  tell  all  the  troubles  Mr.  Totman,  the  butter- 
maker,  has  had  with  his  butter  since  last  spring,  so  I  will  not  recite  them 
to  you  now. 

"I  am  very  much  interested  to  find  out  what  kind  of  growth  or  growths 
there  is  on  this  butter,  particularly  the  red  growth.  He  has  never  noticed 
any  of  this  growth  on  salted  butter.  He  has  never  noticed  any  of  the 
growth  as  long  as  it  stayed  in  his  refrigerator. 

"The  print  which  I  am  sending  you  was  one  of  a  lot,  made  on  November 
25th,  sent  to  New  Haven  and  returned  to  the  creamery  on  December  6th, 
in  practically  the  same  condition  that  it  is  in  now,  showing  that  the  cold 
evidently  checked  the  growth  of  the  mold. 

"In  making  a  careful  examination  of  the  prints  and  molds  used  by  the 
buttermaker,  I  ran  across  four  or  five  cakes  of  cottage  cheese  on  one  of 
the  shelves  in  the  refrigerator,  one  of  which  I  am  sending  you  along  with 
the  butter.  This  was  made  over  a  year  ago  and  has  gone  so  bad  that 
the  mold  even  penetrated  the  parchment  paper  in  which  it  was  wrapped. 
I  have,  of  course,  ordered  that  cleaned  up  and  the  place  thoroughly 
disinfected. 

"I  am  wondering  whether  there  is  any  connection  between  this  and  the 
growth  in  the  butter.  On  the  other  hand,  if  we  can  trace  back  the  growth 
in  the  butter  to  perhaps  one  or  two  of  the  creamery  patrons,  I  may  be  able 
to  find  the  cause  of  the  butter  going  rancid  so  rapidly.  I  am  anxious  to 
see  the  trouble  straightened  out,  if  possible,  because  the  creamery  will  not 
long  exist  if  the  trouble  continues  to  break  out  at  frequent  intervals." 

In  February,  191 5,  we  sent  a  form  letter  to  all  of  the  cream- 
eries of  the  state  asking  for  information  concerning  this  trouble. 
The  replies  received  showed  that  many  were  unacquainted  with 
it,  partly  because  they  did  not  make  unsalted  butter,  but  four 
or  five  reported  more  or  less  trouble  of  this  kind.  Later  in 
the  year  Mr.  Stoddard  made  an  examination  of  two  or  three 
creameries  to  determine,  if  possible,  conditions  favoring  its 
development.  Separation  cultures  were  made  by  Mr.  Stoddard 
from  several  of  the  samples  received  at  different  times,  and  the 
following  fungi  were  obtained : 

(1)  Mucor,  sp.  undet.  (2)  Altemaria,  sp.  undet.  (3) 
Penicillium  roqueforti,  according  to  Thom.  (4)  Oidium  lactis. 
a  common  fungus  of  milk  and  its  products.  (5)  Epicoccum, 
probably  E.  purpurascens.  The  Epicoccum  at  first  was  mixed 
with  the  Oidium  in  our  cultures  and  did  not  form  spores.  We 
thought  it  might  be  an  Oidium  or  Oospora,  Later  Mr.  Stod- 
dard got  it  in  pure  cultures  producing  the  characteristic 
spores  of  several  cells  united  into  a  globular,  semi-sessile  ball. 
This  last  fungus  is  the  one  that  was  responsible  for  the  red 
colonies  in  the  butter.  The  Penicillium  was  responsible  for 
blue-green  and  the  Altemaria  and  'Mucor  for  blackish  growths. 


4-02         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Some  inoculations  on  good  unsalted  butter  were  tried  but  were 
not  very  successful,  in  most  cases  developing  best  when  the 
fungus  worked  down  between  the  tubes  and  the  butter  where 
there  was  little  air  space  and  more  moisture.  There  seemed  to 
be  some  indication,  too,  that  certain  species  followed  in  the  wake 
of  the  others.  However  our  tests  were  not  extensive  enough 
to  be  very  trustworthy.  If  the  inoculations  had  been  made  on 
butter  covered  with  paper  better  results  might  have  been 
obtained. 

Concerning  the  development  of  the  trouble  in  the  creameries, 
etc.,  the  following  information  was  obtained.  The  molds  were 
confined  to  unsalted  butter,  the  salt  evidently  acting  as  a  pre- 
servative. Some  claimed  that  where  the  butter  was  wrapped  in 
paper  dipped  in  hot  brine  they  were  not  so  likely  to  develop. 
Others  claimed  that  when  the  milk  was  pasteurized  there  was 
no  trouble.  Undoubtedly  in  some  cases  the  trouble  was  due  to 
unsanitary  conditions  in  the  dairy  itself,  as  in  the  case  cited  by 
Prof.  Judkins.  Care  in  handling  the  butter  after  it  was  made, 
especially  as  regards  moisture,  cold  storage  and  length  of  time 
the  butter  was  kept,  also  entered  into  the  problem. 

Another  quite  important  factor  was  the  condition  of  the  milk 
when  it  arrived  at  the  creamery.  Most  of  the  fungi'  isolated 
were  common  saprophytic  species  that  easily  develop  in  cattle 
barns  on  moist  hay,  bedding,  silage,  etc.  Petrie  dish  exposures 
by  Mr.  Stoddard  in  two  barns  developed  very  similar  species  to 
those  recorded  here.  The  Epicoccum  was  thus  obtained  both 
in  barns  and  in  one  of  the  creameries  where  this  trouble  developed. 
The  cleanliness  of  the  barn,  the  care  used  in  milking  and  keep- 
ing the  air  free  from  dust  at  that  time  and  the  protection  given 
the  milk  before  delivery,  all  are  factors  determining  the  num- 
ber of  spores  that  will  fall  into  the  milk  and  cause  trouble 
later. 

While  unsalted  butter  is  still  used  to  a  considerable  extent  by 
Jewish  families  and  some  of  the  larger  hotels  and  restaurants, 
the  reason  no  complaints  have  been  made  in  recent  years  is 
probably  because  most  of  the  creameries  of  the  state  have  gone 
out  of  business.  Their  decline  was  due  to  their  inability  to 
compete  with  milk  sold  for  direct  family  use  and  to  the  destruc- 
tive competition  of  the  large  milk  corporations  that  now  dominate 
the  market. 


MOLDS    OF   BUTTER.  4°3 

There  are  comparatively  few  references,  so  far  as  we  have 
found  in  botanical  literature,  concerning  molds  that  cause  trouble 
in  butter.  We  are  indebted  to  F.  C.  Stewart  for  calling  our 
attention  to  several  of  the  following: 

European  investigators  have  done  the  most  work  along  this 
line.  Lafar  and  his  co-editors  (Handb.  Techn.  Myk.  1907  ed.) 
give  resumes  of  most  of  this  work  together  with  references  to 
the  literature.  In  vol.  2,  p.  214,  Cladospori-um  butyri,  a  fat- 
splitting  fungus,  is  mentioned,  especially  in  connection  with 
Oidium  lactis,  as  a  cause  of  rancid  butter;  while,  pp.  220-1, 
bacteria  are  mentioned  as  causing  red  and  blue  specks  in  butter, 
nothing  is  said  about  fungi  causing  similar  color  troubles.  In 
vol.  4,  p.  525,  Mucor  Mucedo  and  M.  racemosus  are  also  men- 
tioned as  fat-splitting  fungi  found  in  butter. 

Gripenberg  (  Milch.  Zeitung  28 :  626-8,  644-6,  662-3.  1899. )  pub- 
lished quite  an  extensive  article  dealing  with  experiments  under 
which  infection  of  butter  takes  place.  He  found  infection  comes 
from  the  wood  of  the  tubs,  the  paper  wrappings  and  the  air. 
The  chief  fungi  responsible  are  Mucor,  Penicillium,  and  Tricho- 
sporium.  Hard  wood  tubs,  thick  paper,  absolute  cleanliness, 
soaking  tubs  and  paper  in  concentrated  salt  solutions  (over  25%) 
or  steaming  paper  and  tubs  are  preventive  measures  recom- 
mended. 

According  to  Stewart,  Happich  (Zeitschr.  Fleisch-  Milch- 
hygiene  11:  297.)  found  Botrytis,  Oidium  lactis,  Penicillium  and 
Mucor  in  moldy  butter.  Hanus  and  Stocky  (Zeitschr.  Unters. 
Nahr.  Genussm.  3:606.  1900.)  report  Mucor  Mucedo  to  be  a 
fat-splitting  agent  in  butter. 

We  found  no  definite  references  in  European  literature  to  red 
spots  in  butter  caused  by  a  fungus,  though  according  to  Saccardo, 
(Syll.  Fung.  4:20.  1886.),  Trabut  reports  Oospora  ruberrima, 
originally  described  by  Saccardo  on  damp  wax  of  wasps,  as 
occurring  on  butter  in  Algiers.  The  spore  masses  of  this  fungus 
are  red. 

In  America,  while  considerable  work  has  been  published  on 
the  bacteria  of  milk  and  its  products,  but  little  along  the  same 
line  has  made  its  appearance  concerning  fungi,  except  that  on 
cheese  by  Thorn  and  others.  However  we  have  found  a  few 
references  to  moldy  butter,  chiefly  relating  to  control  methods. 


404         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Apparently  not  so  much  trouble  is  experienced  now  as  formerly 
because  of  this  advanced  knowledge  of  control  methods. 

Duggar  (N.  Y.  Prod.  Rev.  Amer.  Creamery.  Oct.  27,  1897.) 
in  a  popular  article  was  one  of  the  first,  at  least  among  botanists, 
to  suggest  preventive  measures  for  controlling  molds  of  tub  and 
paper-wrapped  butter.  He  found  tubs  made  of  sap  wood  most 
objectionable,  spreading  from  this  through  the  paper  into  the 
butter.  He  advised  steaming  the  tubs  and  keeping  them  dry ; 
also  treatment  of  paper  and  tubs  with  copper  sulphate. 

Rogers  (Exp.  Sta.  Rec.  14 :  534.  1903.)  is  reported  as  isolat- 
ing a  fat-splitting  torula  yeast  from  several  samples  of  canned 
butter.  Its  action  was  weaker  than  that  of  fat-splitting  molds. 
The  same  author  (U.  S.  Dep.  Agr.  Bur.  Anim.  Ind.  Bull.  89:  7-13. 
1906.  Ibid.  Circ.  130:  1908.)  described  methods  of  "Prevent- 
ing Molds  in  Butter  Tubs"  and  "Paraffining  Butter  Tubs"  in 
the  publications  here  cited  and  especially  recommended  the  paraf- 
fining" of  tubs  giving  directions  and  details. 

About  the  only  article  dealing  with  the  fungi  causing  these 
troubles  is  that  by  Thorn  and  Shaw  (Journ.  Agr.  Res.  3:  301-10. 
1915.)  on  "Moldiness  in  Butter."  They  classify  the  fungi  found 
under  the  following  headings:  (1)  Smudged  or  Alternaria 
type,  including  here  besides  the  Alternaria,  Cladosporium  butyri, 
Stemphylium  butyri  Patt.,  Cladosporium  sp.,  and  our  red  fungus, 
an  undetermined  specimen  of  which  was  sent  them.  (2)  Green- 
mold  type,  including  Penicillium  roqueforti,  P.  expansum,  P. 
chrysogenum,  etc.  (3)  Oidium  type,  producing  various  shades 
of  orange-yellow  by  O.  lactis.  Besides  these  fungi  they  noted 
under  certain  conditions  the  presence  of  Mucor  sps. 

.  INJURIES  AND  DISEASES  OF  PLANTS  ARRANGED  ACCORDING  TO  HOSTS. 

Apple,  Pyrus  Malus. 
Bacterial  Fruit  Spot,  Bacteria  undet.  Plate  XXXIV,  b. 
Early  in  October,  1919,  several  diseased  apples  were  received  for 
examination  from  Mr.  E.  M.  Ives  of  Meriden.  Two  of  these 
presented  an  appearance,  in  certain  areas,  a  little  different  from 
anything  that  we  had  seen  before;  in  fact,  on  superficial  exam- 
ination, these  areas  looked  as  if  they  might  be  due  to  spray  or 
sun  scorch  of  an  unusual  type.  An  examination  of  the  injured 
tissue,    however,    revealed    the    presence    of    such    numbers    of 


DISEASES    OF   APPLE.  4°5 

bacteria  as  to  lead  us  to  the  conclusion  that  these  were,  if  not 
the  primary,  at  least  the  secondary  cause  of  the  trouble.  The 
skin  over  these  extended  irregular  areas  was  slightly  sunken  and 
reddish-brown  in  color,  in  strong  contrast  with  the  normal  red- 
dish skin.  The  parenchyma  cells  immediately  beneath  the  dis- 
eased areas  were  also  reddish-brown,  as  compared  to  the  normal 
white  tissue,  and  were  somewhat  collapsed  with  contents  dead. 
The  bacteria  were  especially  abundant  in  the  intercellular  spaces. 
While  the  apple  showed  injury  by  the  railroad  worms,  these  had 
no  apparent  relation  to  the  bacteria  since  their  channels  were 
not  connected  with  this  injury.  The  photograph  reproduced 
here  gives  a  somewhat  unsatisfactory  view  of  the  trouble  be- 
cause of  the  high  lights  shown,  but  the  principal  diseased  area 
is  in  the  center  from  which  a  strip  of  the  skin  has  been  removed. 

Cultures  were  attempted  by  taking  tissue  from  the  interior 
diseased  parenchyma  and  placing  it  in  test  tubes  of  agar.  Prac- 
tically all  of  these  produced  bacteria  but  they  were  not  pure, 
showing  in  some  cases  yellowish  and  in  others  whitish  growths 
in  the  different  tubes.  The  latter  seemed  the  most  likely  to 
contain  the  injurious  species  but  cultures  made  directly  from 
these  colonies,  without  attempts  to  isolate  a  single  form,  also 
showed  that  they  were  impure.  Further  work  at  this  time  being 
neglected,  the  cultures  were  left  until  too  late  to  properly  isolate 
and  identify  the  organism.  While  these  bacteria  might  have 
been  an  accidental  invasion  following  some  previous  injury,  it 
is  also  possible  they  were  the  pear  blight  organism  on  an  unusual 
part  of  the  host,  since  this  organism  occurred  in  these  orchards 
especially  on  pears,  and  the  owner  kept  bees.  However,  we 
have  seen  no  references  in  literature  where  this  blight  occurred 
on  mature  fruit  after  the  manner  described  here. 

Bark  Canker,  Myxosporium  corticolum  Edg.  This  fungus 
while  not  reported  before  is  evidently  not  a  new  or  uncommon 
one  in  this  state.  It  does  not  seem  to  be  a  very  vigorous  para- 
site as  it  is  often  associated  with  winter  injury  of  the  bark  or 
wood.  When  so  associated  it  looks  much  like  the  black  rot 
canker,  Sphaeropsis  malorum,  with  which  it  is  often  confused, 
especially  as  the  two  are  sometimes  found  in  the  same  collection 
or  even  together  on  the  same  branch.  The  bark  canker  seems 
to  penetrate  less  deeply,  being  confined  to  the  bark  which  may 


406         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

slough  off  and  a  new  growth  free  of  the  fungus  develop  be- 
neath. The  fruiting  pustules  of  the  two  are  also  similar,  but, 
if  the  spores  are  oozing  out,  the  white  tendrils  of  the  bark  canker 
usually  distinguish  it  from  the  black  rot  canker  whose  spores 
are  deeply  colored.  However,  when  young  the  black  rot  spores 
are  also  hyaline  and  about  the  same  size  (perhaps  average 
wider)  and  shape,  so  they  may  be  mistaken  for  each  other.  In 
fact  on  the  winter  injured  specimens  mentioned  in  our  Report 
for  1906,  p.  310,  both  these  fungi  are  present  according  to  our 
recent  examinations,  although  originally  we  reported  only  the 
black  rot.  The  bark  canker  was  called  especially  to  our  atten- 
tion in  the  spring  of  1919  by  specimens  from  Danbury,  which 
contained  both  this  and  to  a  less  extent  the  black  rot  fungus  ; 
it  was  also  found  a  short  time  later  prominent  on  a  small  winter 
injured  tree  at  East  Haven. 

Paddock  (N.  Y.  Agr.  Exp.  Sta.  Bull.  163:203.  1899.  Ibid. 
185  :  211.  1900.)  and  Stewart  et  al.  (Ibid.  191 :  298.  1900.)  were 
the  first  to  make  early  mention  of  this  fungus  which  they  called 
Macrophoma  malorum.  More  recently  Edgerton  (Ann.  Mycol. 
6:48.  1908.)  has  shown  that  this  name  is  a  synonym  of  the 
black  rot  fungus  and  he  has  described  the  bark  canker  as  a  new 
species  and  given  it  the  scientific  name  used  here.  Paddock's 
inoculation  experiments  with  the  fungus  failed  to  show  its 
parasitic  nature;  so  it  is  not  likely  to  prove  a  serious  pest  at 
best. 

Downy  Mildew  Rot,  Phytophthora  cactorum  (Cohn  &  Leb.) 
Schroet.  In  late  August,  1918,  the  writer  received  a  dozen  dried 
apples  from  J.  S.  Adam  of  Canaan,  Conn.,  which  had  been  stored 
in  paper  bags  since  the  previous  fall.  These  apparently  had  not 
rotted  but  dried  down  into  the  preserved  specimens  much  like 
raisins.  They  were  so  full  of  sugar  that  Mr.  Adam  wanted  to 
know  if  this  was  an  unusual  occurrence.  Upon  examining  the 
reddish  preserved  tissues  microscopically,  we  were  much  surprised 
to  find  an  abundance  of  a  non-septate  guttulate  mycelium,  of 
variable  diameter,  much  like  that  of  Phytophthora.  Cultures 
attempted  from  this  tissue  failed,  however,  to  produce  any 
growth  so  the  mycelium  was  evidently  dead  at  this  time.  The 
next  year  stored  pears  sent  from  Bridgeport  showed  the  same 
type  of  non-fruiting  mycelium  present ;  in  this  case  we  were  able 


DISEASES    OF   APPLE.  4°7 

to  isolate  the  fungus,  produce  its  fruiting  stage  in  cultures,  and 
so  accurately  establish  its  identity  as  above  named.  A  more 
complete  statement  concerning  the  fungus  is  given  in  this  paper 
under  Pear,  q.  v. 

Heart  Rots,  Polyporus  admirabilis  Pk.  and  P.  (Spongipellis) 
galactinus  Berk.  Dodge  (Myc.  8:  5-14.  Ja.  1916.)  in  his  article 
entitled  "Fungi  Producing  Heart-Rot  of  Apple  Trees"  describes 
these  two  species  as  partly  responsible  for  this  trouble.  The 
former  occurs  singly,  or  more  frequently  in  calla-lily-like  clusters, 
on  the  trunks  showing  as  large  milk-white,  centrally  depressed, 
fragile,  fleshy  fungi  that  on  drying  become  hard  and  leathery  and 
have  a  peculiar  "glace  kid  glove"  feel  to  the  upper  surface. 
His  observations  on  the  species  were  made  chiefly  in  Litchfield 
Co.,  Conn.  He  collected  specimens  at  the  Columbia  Camp  and 
vicinity  near  Litchfield,  but  he  reports  other  specimens  from 
Redding.  In  May,  1918,  the  writer  also  collected  an  old  speci- 
men of  this  species  on  a  dead  apple  tree  at  Union,  Conn. 

The  second  species,  P.  galactinus,  is  smaller  but  in  its  bracketed 
group  becomes  even  more  conspicuous  and  is  of  about  the  same 
color.  Dodge  reports  this  from  the  same  two  localities  as  the 
other  species.  Recently  Murrill  (Myc.  11:310.  1919.)  also 
noticed  it  on  apple  trees  in  Eastern  Connecticut,  and  the  writer 
collected  it  on  a  living  apple  tree  at  Norfolk  in  1916.  Others 
have  also  reported  it  from  Connecticut.  Both  of  these  fungi, 
wmile  causing  a  rot  of  the  heart  wood,  do  not  seem  to  especially 
attack  the  living  tissue  and  so  cause  much  less  damage  than  if 
that  were  the  case. 

White  Heart  Rot,  Fomes  igniarius  (L.)  Gill.  We  have 
seen  this  fungus  several  times  in  this  state  upon  living  apple 
trees.  The  oldest  specimen  we  have  in  the  herbarium  is  from 
Norfolk,  collected  in  September,  191 1,  and  it  was  found  there 
again  in  19 16.  It  was  also  collected  twice  from  an  apple  tree 
at  Milford,  the  latter  year.  It  is  treated  more  fully  under 
Oak,  q.  v. 

Hail  Injury.  In  one  of  our  spray  bulletins,  which  see 
(Conn.  Agr.  Exp.  Sta.  Rep.  1911 :  382.  1912.),  we  briefly  men- 
tioned and  showed  a  half  tone  of  hail  injury  to  the  apples  at 
our  Mt.  Carmel  farm.  Hail  storms  coming  on  the  young  fruit 
produce  in  time   some   misshapening  of   the   mature   fruit  but 


408         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

especially  show  their  effect  as  conspicuous  russeted  or  corky 
spots  on  the  skin.  In  1918  we  heard  of  more  or  less  injury  at 
Wallingf ord  to  the  fruit  but  had  particularly  called  to  our  atten- 
tion hail  injury  to  the  twigs  in  the  Bellinger  orchard  at  Litchfield. 
Mr.  Stoddard,  who  examined  the  orchard  to  obtain  data,  found 
that  it  appeared  on  the  1  to  3  year  old  twigs  on  a  certain  side 
of  the  trees  and  the  owner  recalled  a  severe  hail  storm  of  the 
previous  year  that  came  from  that  direction.  The  beating  of  the 
hail  had  so  bruised  the  bark  that  a  callous  growth  was  formed 
beneath,  causing  the  bark  to  split  open  and  reveal  the  slight 
swelling. 

Malformed  Twigs  and  Aerial  Crown  Gall,  Pseudomonas 
tumefaciens  (Sm.  &  Town.)  Stev.  Plates  XXXV,  a-b.  Besides 
the  hail  injury  mentioned  above,  we  have  received  at  various  times 
for  identification  peculiar  malformations  of  apple  twigs,  as  to  the 
cause  of  which  we  were  not  always  sure.  Two  of  these  are 
shown  in  the  illustrations  given  here.  The  one  that  is  shown  in 
Fig.  a,  we  have  usually  called  aerial  crown  gall.  The  ordinary 
nursery  type  of  galls  at  the  base  of  stems  and  the  hairy  root, 
we  have  mentioned  in  our  Report  for  1903,  but  the  specimens 
considered  here  have  been  studied  without  a  chance  to  examine 
the  trees  in  the  orchard  and  thereby  determine  the  condition  of 
their  roots.  These  aerial  galls  occur  on  both  young  and  old 
trees.  Hedgecock  (U.  S.  Bur.  PI.  Ind.  Bull.  186:15.  1910.) 
pictures  (Plate  V,  Fig.  1)  and  describes  this  form  and  associates 
it  with  the  hairy  root  type  of  crown  gall.  Garman  (Ky.  Agr. 
Exp.  Sta.  Bull.  93:106.  1901.)  previously  pictured  and  de- 
scribed a  similar  trouble  as  a  "Knot  Disease,"  and  while  he 
thought  it  contagious  he  did  not  associate  it  with  the  crown  gall 
which  he  described  in  the  same  bulletin. 

This  trouble  is  usually  found  by  the  apple  growers  in  late 
winter  when  pruning  the  trees  and  the  specimens  sent  us  show 
as  a  distinct  lateral  growth  on  the  branch  or  as  a  swelling  at 
the  base  of  a  side  branch,  Occasionally  it  takes  the  form  of  a 
distinct  spherical  knob  like  the  typical  basal  crown  gall.  More 
frequently  it  forms  flattened  growths,  at  first  perhaps  smooth 
or  with  smaller  knobs  on  it  but  usually  with  an  abundance  of 
small  closely  packed  protuberances  something  like  adventitious 
buds.     These  affected  tissues  die  prematurely  so  that  we  have 


DISEASES    OF    APPLE.  4°9 

never  seen  these  "buds"  develop  further.  Some  of  these  areas 
on  larger  branches  reach  a  lateral  diameter  of  two  inches,  or  where 
abundant,  individuals  may  partly  coalesce  into  even  larger  areas, 
but  they  rarely  grow  out  half  an  inch  beyond  the  surface  of  the 
bark.  While  we  have  never  heard  of  these  growths  killing 
the  whole  tree,  where  extending  completely  around  the  branches 
as  they  sometimes  do,  they  killed  these  in  time. 

The  specimens  preserved  in  the  Station's  herbarium  and  let- 
ters show  data  as  follows :  ( i )  W.  T.  Coe  &  Son,  Durham,  Apr., 
1907,  branches  y2  to  iy2  inches  diameter,  in  center  of  tree,  with 
numerous  irregular  swellings  with  abundance  of  "buds"  on 
these.  (2)  J.  O.  Landon,  Norwich,  Mar.,  191 1,  rounded  smooth 
typical  gall  on  ^4  incn  branch  showing  winter  injury  of  heart 
wood.     Reported  several  galls  on  a  single  12-15  year  old  tree. 

(3)  E.  S.  Lovell,  Newton,  Apr.,  1913,  several  irregular  and 
roughened  swellings,  largest  about  1  inch  diameter,  around 
twigs  about  half  their  size.     Three  Sour  Bough  trees  infected. 

(4)  F.  P.  Tolles,  Terryville,  Apr.,  191 5,  branches  2  inches  diame- 
ter with  large  flattened  areas  with  abundance  of  "buds."  (5) 
C.  E.  Shepard,  Mt.  Carmel,  Apr.,  19 17,  branches  on  young  tree, 
shown  in  photograph.  (6)  H.  J.  Tillson,  County  Agent,  found 
in  orchard  near  Norwich,  Mar.,  1917,  same  type  as  Lovell  speci- 
mens ;   one  tree  badly  infected. 

The  other  type  of  abnormal  growth  has  been  sent  less  fre- 
quently for  identification,  and  we  are  even  less  certain  of  its 
origin.  The  specimens,  illustrated  in  Fig.  f,  were  received  in 
March,  1913,  from  J.  T.  Cullen,  Derby.  These  show  young 
twigs  with  an  evident  swelling  below  a  terminal  bud  or  branch 
that  has  been  killed  and  a  new  branch  developed  from  a  lateral 
bud.  The  swelling  is  largely  due  to  an  abnormal  development 
of  spongy  parenchyma  which  at  least  in  some  cases  dies  pre- 
maturely. One  could  easily  imagine  such  a  growth  due  to  winter 
injury  of  the  terminal  branch  or  bud,  to  insect  stings  or 
mechanical  injury  in  some  way.  Quite  frequently  one  sees  in 
orchards,  especially  on  certain  varieties,  as  Ben  Davis,  very  simi- 
lar natural  swellings  apparently  due  to  abundance  of  food  mate- 
rial stored  in  the  tip  of  the  year's  growth  that  retains  the  swell- 
ing somewhat  the  next  year  at  the  base  of  that  year's  growth. 
No   injury   to   the   tissues    follows    in   these    cases.     There    are 


4IO         CONNECTICUT    EXPERIMENT    STATION   BULLETIN   222. 

cases  where  such  malformations  as  described  here  are  claimed 
to  be  the  result  of  the  crown  gall  bacteria.  Hedgecock  (loc.  cit., 
Plate  IV,  figs.  1-2)  shows  by  his  illustrations  and  his  statement 
that  they  are  the  "early  stage  of  the  aerial  form  of  the  'Hairy 
Root'  "  and  finally  develop  into  the  type  of  trouble  first  men- 
tioned in  this  article. 

A  very  similar  trouble  to  this  on  pear  twigs  we  have  described 
elsewhere  in  this  Report  as  due  to  winter  injury.  Because  of 
our  uncertainty  that  the  crown  gall  germ  is  always  responsible 
for  these  two  injuries  they  are  described  here  both  as  physiologi- 
cal and  bacterial  troubles. 

Mice  Girdle.  Each  year,  during  the  winter  season,  mice 
cause  more  or  less  injury  to  trees  by  eating  off  the  bark  at  their 
base.  Some  years,  however,  the  injury  is  much  more  serious  than 
in  others,  and  when  there  is  an  abundance  of  snow  on  the  ground 
the  injury  seems  to  be  worse.  Apple  trees  suffer  more  than 
any  others  though  complaints  have  been  made  of  injury  to  peach, 
maple,  Scotch  and  white  pine.  The  winter  of  1919-20,  with  its 
abundant  snowfall,  apparently  was  the  worst  of  any  yet  noticed. 
Even  poison  ivy  was  girdled  along  fence  rows.  In  a  nursery  we 
saw  considerable  injury  to  Japanese  maples  and  other  ornamental 
plants.  Reports  were  received  of  serious  injury  in  many  apple 
orchards,  and  to  a  less  extent  in  peach  orchards,  to  both  young  and 
old  trees  so  that  many  thousands  of  fruit  trees  in  the  state  were 
thus  girdled.  Most  of  this  injury  occurred  below  the  snow  line. 
We  will  not  discuss  the  trouble  further  here,  but  refer  the  reader 
to  the  special  article  on  this  subject  by  Mr.  Stoddard  recently 
issued  by  the  Station  (Bull,  of  Inf.  10:  1-7.  Figs.  1-8.  Mr. 
1920.). 

Smoke  Injury.  In  July,  1919,  a  letter  was  received  by  the 
Station  from  C.  A.  Burley  of  Stamford  in  which  he  wrote :  "I 
have  an  orchard  which  (I  think)  is  being  killed  by  smoke  from 
a  factory  alongside  of  it.  In  fact  several  of  the  trees  are  al- 
ready dead  and  the  others  very  weak.  I  would  like  very  much 
if  you  could  send  someone  to  look  over  the  situation."  Soon 
afterward  the  writer  and  the  state  forester,  Mr.  Filley,  went 
to  Stamford,  and  with  Mr.  F.  A.  Bartlett  and  one  of  the  parties 
interested  examined  the  orchard  and  the  vicinity  for  the  cause 
of  the  trouble. 


DISEASES    OF   APPLE.  411 

A  suspicious  thing,  in  the  mind  of  the  writer  at  least,  was 
the  presence,  about  in  a  direct  line  a  quarter  of  a  mile  away 
but  lower  down  near  a  stream,  of  a  chlorine  factory  that  was 
used  during  the  war  by  the  government  for  making  chlorine  gas 
but  now  abandoned.  An  examination  of  the  vegetation,  espe- 
cially the  trees  immediately  around  this  factory,  showed  no  in- 
jury except  to  a  few  trees  on  the  edge  of  the  stream  into  which 
had  been  emptied  considerable  chemical  refuse  from  the  factory. 
In  other  words  as  there  seemed  to  be  no  indication  here  of 
injury  to  the  trees  or  herbaceous  vegetation  from  possible  escap- 
ing fumes,  there  was  no  likelihood  of  the  trouble  in  the  orchard 
being  due  to  such  a  cause. 

The  orchard,  however,  bordered  directly  on  one  side  of  the 
buildings  of  a  bronze  factory,  through  the  open  windows  of 
which  were  blown  the  minute  particles  from  the  burnished 
bronze.  More  or  less  of  this  dust  settled  upon  the  surrounding 
vegetation  and  could  be  distinctly  seen  as  minute  golden  particles 
on  the  apple  leaves  even  some  distance  away.  The  man  who 
showed  us  around  thought  that  the  bronze  dust  was  responsible 
for  the  injury  to  the  trees.  At  first  sight  this  also<  seems  plausi- 
ble, as  the  apple  leaves  where  the  dust  was  most  abundant 
had  numerous  small  reddish  specks  often  immediately  under  the 
bronze  particles.  An  examination  of  the  vegetation  immediately 
under  the  factory  windows  where  the  dust  was  thickest,  showed 
no  evident  injury  on  such  tender  leaves  as  pokeweed,  burdock, 
Bidens,  etc.  It  seemed  probable,  therefore,  that  this  dust  caused 
no  harm,  unless  possibly  on  long  standing  some  unknown  chemi- 
cal change  took  place  that  produced  these  specks  and  even  then 
this  would  not  account  for  the  death  of  the  trees  and  the  severe 
scorching  of  the  foliage  elsewhere.  The  smoke  from  the  factory 
was  carried  off  by  a  high  stack,  with  the  wind  mostly  taking  it 
away  from  the  trees,  thus  eliminating  this  as  a  factor.  In  the 
rear  of  the  factory,  was  a  temporary  incinerator  with  a  low  stack 
for  burning  rubbish  including  the  waste  that  was  used  in  burnish- 
ing the  bronze.  The  smoke  from  this  was  strong  and  could 
be  easily  carried,  with  the  wind  in  the  right  direction,  over  the 
apple  trees.  In  fact  it  was  in  an  extension  of  the  orchard  near- 
est this  that  most  of  the  dead  trees  occurred.  From  what  we 
have  seen  of  smoke  injury  elsewhere,  this  seemed  to  us  to  be 


412         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

the  most  logical  source  of  the  injury.  Just  what  chemical  mat- 
ter was  included  in  this  waste  that  could  cause  the  injury  we 
did  not  determine,  but  if  sulphur  was  present  it  could  have  been 
responsible. 

Winter  Injury  Cankers.  The  severe  winter  of  1917-1918  did 
great  harm  to  various  trees  in  this  state,  especially  to  cultivated 
ones  and  particularly  to  peaches  and  apples.  We  have  in  previ- 
ous Station  Reports  discussed  various  forms  of  winter  injury  to 
the  apple,  and  in  the  Rept.  of  the  Conn.  Pom.  Soc,  vol.  21,  p.  102, 
1919,  have  given  a  brief  resume  of  these  including  the  trouble 
mentioned  here.  We  wish  in  this  note  merely  to  mention  this 
unusual  form  of  winter  cankers  not  noted  before  in- our  Station 
Reports.  One  of  the  worst  injured  orchards  that  we  saw  was 
that  of  W.  B.  Johnston,  of  South  Meriden,  who  had  us  examine 
it  in  June  as  he  thought  he  had  some  unusual  disease. 

The  orchard,  chiefly  Baldwins,  was  on  an  exposed  hill  that 
got  a  full  sweep  of  the  winter  winds  and  had  shown  no  such 
injury  the  previous  season.  Trees  that  bore  heavily  the  previous 
fall  were  those  that  suffered  the  most  winter  injury.  Besides 
the  dead  and  badly  injured  trees,  there  were  some  that  showed 
irregular  dead  areas  on  the  trunk  or  elongated  dead  areas  on  the 
limbs  that  looked  like  disease  cankers  as  they  were  sharply  marked 
off  by  cracks  in  the  bark  from  the  living  tissues.  Often  these 
showed  fruiting  pustules,  thus  increasing  the  impression  of  their 
fungous  origin  to  one  not  acquainted  with  the  facts  of  the  case. 
A  peculiarity  of  the  cankers  in  many  cases  was  their  situation 
on  the  lower  side  of  branches  with  the  upper  side  healthy  or  only 
slightly  injured!  Just  what  caused  this  difference  in  suscepti- 
bility to  injury  we  do  not  know.  Possibly  the  tissues  of  the 
upper  side  were  more  matured  or  contained  less  water.  Such 
cankers  on  the  under  side  of  branches  were  not  infrequent  in 
other  orchards   following  this   severe  winter. 

Ash,  White,  Fraxinus  americana. 
Anthracnose,  Gloeosporium  aridum  Ell.  &  Holw.  We  have 
reported  anthracnoses  before  on  maple,  oak  and  some  other 
trees,  but  in  the  summer  of  1919  we  received  for  the  first  time 
specimens  on  white  ash.  They  were  sent,  early  in  June,  both  by 
Miss   Jessie    H.    Brown    from    Lyme   and   H.    O.    Taylor    from 


DISEASES    OF    WHITE    ASH.  413 

Cobalt,  who  complained  of  the  trouble  as  a  serious  one  causing 
more  or  less  defoliation  of  their  shade  trees.  In  the  first  case 
at  least,  the  leaves  were  also  attacked  by  the  rust  mentioned  be- 
low. The  disease  appeared  on  the  leaves  as  they  were  reaching 
maturity  causing  a  scorch-like  burn  usually  involving  consider- 
able area  from  the  margin  inward;  occasionally  there  were 
smaller  isolated  spots  within.  The  diseased  area  was  somewhat 
translucent,  of  a  light  or  yellowish-brown-  color,  sharply  marked 
off  from  the  healthy  tissues  and  easily  broken  when  dry.  The 
very  inconspicuous  fruiting  pustules  were  seen  with  a  hand  lens 
more  or  less  abundantly  imbedded  in  the  lower  surface.  The 
wet  spring  weather  was  very  favorable  for  this  as  well  as 
other  true  anthracnoses. 

Four  different  species  of  anthracnose  have  been  reported  on 
this  host  and  at  least  one  or  two  on  other  species  of  ash.  So 
far  as  we  can  determine  from  the  printed  description,  our  speci- 
mens agree  best  with  the  species  given  above  which  was  published 
by  Ellis  and  Everhart  in  the  Journ.  Myc,  p.  21,  1887.  The 
specimens  upon  which  this  species  was  based  were  received  from 
J.  J.  Davis  of  Racine,  Wis.  Davis  (Trans.  Wise.  Acad.  Sci. 
Arts  9:169.)  in  1892  erroneously  gave  the  authority  for  the 
name  as  E.  &  E.  He  writes,  "Abundant.  When  developing 
vigorously  on  exposed  trees  it  attacks  one  edge  of  the  leaf,  caus- 
ing it  to  curl  toward  the  affected  side.  When  less  vigorous  on 
leaves  of  shaded  trees  it  occurs  on  roundish  spots  about  5  mm. 
in  diameter." 

The  spores  as  we  find  them  are  hyaline,  oblong  or  broadly 
oblong,  slightly  pointed  at  the  ends,  straight  or  very  slightly 
curved,  6-iO/x  by  2.5  -  3.5^  but  chiefly  7-9^  by  3/x.  Gloeosporium 
irregulare  Peck,  described  shortly  after  this  species,  does  not 
seem  to  differ  materially  from  it  except  in  the  greater  width  of 
the  spores  (4-5/*)  as  given  by  Peck.  Recently  we  have  received 
typical  specimens  of  G.  aridum  from  Davis,  and  of  G.  irregulare 
from  House,  and  both  express  the  opinion  that  they  are  the  same 
species.  Our  examination  of  these  specimens  also  confirmed  our 
suspicions  that  this  was  the  case.  Dr.  House  writes,  "I  think 
there  is  no  question  as  to  the  identity  of  irregulare  with  aridum, 
apparent  differences  in  the  measurements  given  in  the  description 
are  not  borne  out  in  the  specimens.     I  enclose  a  bit  of  the  type." 


414         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

Rust,  Aecidium  Fraxini  Schw.  Plate  XXXV,  c.  We  have  il- 
lustrated and  briefly  described  this  rust  in  previous  Reports 
(Conn.  Agr.  Exp.  Sta.  Rep.  1903:304.  Ibid.  1911-12 :' 343.) 
as  occurring  not  uncommonly  on  the  blades  and  petioles  of  the 
white  ash  in  this  state.  During  the  early  summer  of  19 19  it 
was  more  abundant  than  we  have  ever  seen  it  before.  It  was 
sent  in  several  times  as  causing  more  or  less  injury  to  the  lawn 
trees  and  was  said  to  cause  severe  defoliation  in  one  case.  In 
our  collection  this  year  we  found  the  rust  not  only  on  the  blades 
and  petioles  but  also  on  the  young  stems  of  this  year's  growth, 
the  maturing  winged  seeds  and  the  staminate  blossoms  which 
had  been  curiously  transformed  through  the  action  of  the  phytop- 
tus  mite  occurring  on  this  host.  The  mycelium  causes  more  or 
less  distortion  of  the  infected  parts  and  this  is  especially  so  on 
the  branches,  where  it  produces  gall-like  growths,  covered  with 
the  aecial  stage,  and  often  involving  the  young  axial  parts,  as 
shown  in  the  illustration.  When  young  the  aecia  are  elongated 
but  wear  away  in  time  to  short  cups.  Farlow  (Proc.  Soc.  Prom. 
Agr.  Sci.  9:26.  1888.)  reported  a  serious  and  extended  out- 
break of  this  fungus  in  1885.  Arthur  (Bot.  Gaz.  29:275.)  re- 
ports cultures  made  in  1899,  and  several  times  since,  with  the  III 
stage  of  a  Puccinia  from  Spartina  sps. ;  he  produced  the  I  stage 
on  Fraxinus  -lane eolata.  He  calls  the  fungus,  therefore,  Puccinia 
fraxinata  (Schw.)  Arth.  So  far  as  we  have  found,  no  one  has 
infected  other  species  of  Fraxinus  with  the  Spartina  rust. 
Arthur  however  failed  in  several  attempts  with  other  genera  in 
the  same  family  as  Fraxinus.  While  this  rust  is  common  along 
the  Sound  where  Spartina  also  occurs,  we  have  often  seen  ash 
trees  badly  affected  quite  removed  from  any  specimens  of  it. 
Our  efforts,  however,  to  obtain  any  further  clues  of  relationship 
met  with  failure.  We  tried  several  times  to  inoculate  species  of 
Agropyron  repens,  Poa  pratensis,  Spartina  (large  and  small) 
sps.,  and  even  leaves  of  Fraxinus  americana,  with  the  I  spores 
from  the  last  host  without  result. 

Asparagus,  Asparagus  officinalis. 
Anthracnose,     Colletotrichum    sp.      On    Burr's    Mammoth 
Asparagus  at  the  Station  farm,  the  latter  part  of   September, 
1919,  we  noticed  a  conspicuous  disease  on  the  green  stems  that 


DISEASES    OF   ASPARAGUS.  4J5 

we  had  not  seen  before.  This  was  causing  more  or  less  injury 
to  the  infected  plants.  Irregular,  often  elongated,  grey  areas, 
of  greater  or  less  extent,  appeared  in  the  normal  green  skin;  in 
these  were  numerous  very  small  but  conspicuous,  black  fruiting 
pustules.  The  center  of  these  often  showed  a  white  spot  evi- 
dently where  the  spores  were  discharged.  The  spores  are 
hyaline,  narrowly  to  broadly  oblong,  often  somewhat  pointed  at 
one  end  and  12-17^  long  by  4-6/x  wide.  The  fungus  is  evi- 
dently that  briefly  described  and  pictured  by  Halstead  (N.  J. 
Agr.  Exp.  Sta.  Rep.  1896:  410.)  in  1897  but  of  which  he  gives 
no  description  of  the  spores,  etc.  There  are  no  setae  on  the 
fruiting  pustules  of  our  specimens  so  that  the  fungus  looks  as 
much  like  a  Phoma  as  a  Collet  otitic  hum.  Several  species  of  each 
of  these  genera  have  been  described  on  asparagus,  but  all  appear 
to  be  on  the  dead  stems  and  none  quite  like  ours.  We  have  found 
no  further  reference  to  Halstead's  Colletotrichum  sp.,  and  Cook 
writes  that  there  are  no  specimens  of  it  in  the  herbarium  at 
New  Brunswick.  On  our  specimens,  often  in  the  same  spots, 
there  is  also  a  Fusarium,  previously  mentioned  by  us  (Rep. 
1903:305.).  This  probably  has  no  connection  with  the  Colleto- 
trichum and  seems  to  form  more  definite  elliptical  or  elongated 
spots  with  a  distinct  purplish  border,  but  it .  is  difficult  to  tell. 
in  some  cases,  which  fungus  caused  the  spots.  It  may  be  that 
both  are  languishing  parasites  on  the  older  stems  or  that  one 
follows  the  other  as  a  lesser  parasite. 

Fasciation.  Harshberger  in  his  book  (Mycol.  Plant  Path.: 
329.)  describes  fasciation  as  follows:  "Fasciation  in  its  simplest 
form  consists  of  a  flat,  ribbon-like  expansion  of  stem,  branch, 
flower  clusters,  flowers  and  fruits  which  may  be  cylindric  below, 
but  flattened  above."  Sorauer  (Handb.  Pflanzenkr.  1:332.) 
says  concerning  these  f asciations :  "We  may  likewise  consider 
as  due  to  local  over-nutrition,  the  condition  arising  when  a  cylin- 
drical branch  becomes  broad  and  flattened.  It  then  looks  as 
if  a  number  of  branches  had  grown  together;  nevertheless, 
this  is  only  rarely  the  case,  for  almost  always  only  a  single 
branch  is  involved,  which,  by  broadening  its  vegetative  point,  no 
longer  has  a  vegetation  cone  at  its  apex  but  a  comb-like  vegetative 
surface."  The  last  writer  also  states:  "We  have  seen  already 
in  roots  held  fast  between  split  rocks  that  pressure  from  two 


416  CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

opposite  sides  may  give  the  axis  a  band-like  form.  Under  cer- 
tain circumstances  such  a  changed  direction  or  growth  may 
continue  if  the  cause  of  arrestment  itself  has  disappeared." 
Cowles  (Text  Book  Bot.  2:786.)  writes:  "The  phenomenon  is 
not  well  understood,  but  often  it  is  believed  to  be  associated 
with  'over  nutrition' ;  sometimes  it  is  produced  by  mechanical 
causes,  or  by  insect  or  fungal  activities  (as  in  (Enothera) .  Fas- 
ciation  sometimes  appears  to  be  inheritable,  but  this  remains  to 
be  established,  at  least  as  a  general  proposition." 

Mr.  Frank  Hanchett  of  Falls  Village,  Conn.,  brought  to  the 
Experiment  Station  during  the  winter  of  1918  a  specimen  of 
asparagus  (partly  shown  in  Plate  XXXVI,  a,  here)  taken  from 
his  garden  the  summer  previous,  that  showed  evident  fasciation. 
The  stem  was  flattened  so  that  when  green  it  was  two  and  a 
half  inches  wide  across  the  base  as  against  half  an  inch  in  thick- 
ness. The  stem  as  brought  to  us  was  about  two  feet  long  and 
was  flattened  the  entire  length.  The  apex  was  narrowed  and 
twisted  into  an  irregular  spiral  coil  of  two  and  a  half  turns. 
About  half  way  down,  the  specimen  branched  but  the  second 
branch  was  broken  off  a  short  distance  above  its  origin  so  the 
nature  of  its  apex  was  not  disclosed.  Sections  made  through  the 
stem  showed  abundance  of  the  mycelium  of  some  fungus  scat- 
tered somewhat  irregularly  through  its  length.  These  threads 
were  much  more  abundant  in  spots,  evidently  developing  best  in 
the  vicinity  of  the  fibro-vascular  bundles,  especially  in  the  pith 
cells  surrounding  them  and  in  the  vascular  ducts.  Concerning 
the  identity  of  the  fungus  we  could  not  be  sure  because  no 
definite  spores  were  seen,  but  it  appeared  to  be  a  Fusarium. 
There  may  have  been  some  connection  between  the  presence  of 
the  fungus  and  the  fasciation,  but  we  cannot  be  sure. 

Keeping  this  malformation  in  mind  we  unearthed  several  ex- 
amples of  fasciation  of  asparagus  during  the  spring  of  1918. 
These  came  from  Milford,  North  Haven  and  Middlebury,  so 
this  trouble  cannot  be  considered  very  rare.  We  did  not  find 
in  these  subsequent  specimens  the  mycelium  of  any  fungus  though 
all  were  not  carefully  examined.  The  largest  of  the  two  or 
three  specimens  from  the  Whittemore  estate  at  Middlebury  was 
about  3  feet  long  and  showed  short  bifurcated  and  slightly  coiled 
tips.     The   specimen   from  the   Clark  Wilcox  place  at   Milford 


DISEASES    OF   BEANS.  4X7 

was  by  far  the  most  striking,  being  at  least  five  feet  long  and  the 
flattened  side  of  the  stem  three  inches  wide,  with  numerous 
branches  scattered  along  its  sides  in  the  axils  of  the  scale-like 
leaves,  as  was  the  case  with  the  other  specimens.  The  stem  was 
coiled  in  one  complete  turn  near  the  center  but  the  nature  of 
the  tip  was  obscured  though  probably  slightly  bifurcated. 

In  19 19  market  agent  Stack  brought  us  a  specimen  purchased 
in  the  New  Haven  market,  and  in  1920  other  specimens  were 
found  in  the  Station's  asparagus  bed.  Efforts  in  1920  to  pro- 
duce this  flattening  by  various  artificial  methods  involving  pres- 
sure on  the  growing  tips  were  apparently  not  successful;  but 
further  work  along  this  line  will  be  done. 

Besides  these  fasciations  of  asparagus,  we  briefly  describe  in 
this  Report  somewhat  similar  troubles  on  Larkspur,  Pea  Shrub, 
Rose  and  Sumac,  and  previously  (Rep.  1913:  6.  1914.)  we  have 
described  and  figured  the  same  thing  on  a  young  apple  twig. 
Besides  the  flattening  of  the  stem,  common  characters  with  most 
of  these  fasciations  are  the  bifurcation  and  coiling  of  the  tips. 

Bean,  Phaseolus  vulgaris. 
Bacterial  Wilt,  Bacteria  sp.  Plate  XXXVI,  c.  Several 
times  in  the  early  summer  of  1918,  we  had  complaints  of  young 
beans  in  war  gardens  dying  from  a  scorch-like  wilt.  We  did  not 
have  opportunity  to  thoroughly  investigate  all  of  these  complaints, 
but  such  plants  as  we  did  examine  led  us  to  conclude  that  the 
trouble  was  not  primarily  a  sun-scorch  but  resulted  from  in- 
vasion of  the  vascular  system  by  bacteria.  These  eventually 
more  or  less  completely  cut  off  the  water  supply,  with  resulting 
wilting  and  scorching  of  the  leaves  under  exposure  to  bright 
sunlight.  The  spring  and  early  summer  had  been  unusually 
wet  and  so  favored  bacterial  invasion  of  the  stem  through  in- 
juries  of  the  roots.  Some  of  the  specimens  examined  showed 
as  yet  little  wilting  of  the  foliage  but  evident  invasion  of  the 
vascular  ducts  both  in  the  stems  and  the  leaves.  Often  the 
invaded  tissues  were  apparently  little  injured;  occasionally  bac- 
teria were  found  in  the  pith  of  the  stem  as  well  as  in  the  ducts. 
A  peculiar  case  shown  us  by  F.  J.  Reveley,  supervisor  of  war 
gardens  at  East  Haven,  was  in  a  garden  of  eight  rows  of  beans, 
four  of  which  had  the  trouble  badly,  while  the  other  four  were 


41 8         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

apparently  free.  Some  bacteria,  however,  were  found  in  the 
plants  of  the  unaffected  rows.  The  only  difference,  so  far  as 
we  could  determine,  between  the  affected  and  unaffected  was 
that  the  latter  had  a  little  more  shade! 

While  there  is  a  bacterial  disease  causing  a  spotting  of  the 
leaves  of  beans,  the  trouble  mentioned  seems  to  be  another  thing 
altogether.  It  is  more  like  the  bacterial  wilt  of  cucurbits,  but 
whether,  as  in  that  case,  caused  by  a  definite  organism  we  do 
not   know.     We   have    seen    no    references    describing    such    a 

trouble  of  beans. 

Beech,  Fagus  sps. 

Gas  Injury.  Through  the  kindness  of  Mr.  G.  F.  Herthal, 
tree  expert,  the  writer,  with  the  State  Forester,  was  shown  in 
August,  1919,  a  couple  of  beech  trees  on  the  Nathaniel  Wrheeler 
Estate  at  Bridgeport,  that  developed  the  unusual  injuries  men- 
tioned here.  The  first  tree  was  near  a  driveway  under  which 
passed  the  gas  supply  to  the  house.  The  tree  for  at  least  the 
past  two  years  had  developed  a  serious  injury  of  the  leaves  soon 
after  they  matured.  This  showed  as  a  scorch,  chiefly  at  the 
margins,  and  caused  more  or  less  defoliation.  Otherwise  the 
tree  looked  healthy  and  there  was  no  apparent  fungous  or  insect 
cause  for  the  trouble.  As  the  scorch  had  a  similar  appearance 
to  gas  injury  that  we  have  seen  on  maple  trees  on  the  streets,  we 
finally  concluded  that  there  was  a  slight  leak  from  the  gas  pipe  in 
the  road  that  caused  injury  to  the  roots  and  thereby  affected  the 
leaves. 

Lightning  Injury.  In  this  same  yard  there  was  a  very  old  and 
noble  copper  beech  which  a  number  of  years  before  had  been 
struck  by  lightning.  The  most  evident  effect  was  the  killing  of 
the  bark  at  the  base  of  the  tree  so  that  at  this  time  it  was  entirely 
girdled,  except  for  a  slight  connection  on  one  side  with  a  large 
root.  While  the  tree  had  been  trimmed  of  a  large  dead  branch 
in  the  past  and  had  one  nearly  dead  main  branch  on  one  side,  it 
still  maintained  evident  vigor  of  the  main  very  large  branches 
despite  this  almost  complete  girdling  at  the  base. 

Bitter  Sweet,  Celastrus  scandens. 
Chlorosis.     This  was  merely  a  case  of  yellowish-white  spotting 
of  the  leaves,  most  frequently  near  the  margin.     Some  leaves 
had  yellowish  areas   instead  of  the   small   definite   spots.     This 


WINTER   INJURY    OF    BOX.  419 

trouble  may  have  resulted  from  some  insect  sucking  the  juices 
from  the  leaves  when  they  were  quite  young-,  but  it  was  more 
likely  due  to  the  late  frosts  that  came  early  in  May,  as  we  have 
seen  somewhat  similar  injury  caused  on  other  plants.  See  Frost 
Injury  under  Tobacco.  The  specimens  were  found  in  June,  1919, 
on  a  wild  plant  at  East  Haven,  but  may  be  looked  for  on  culti- 
vated ones,  as  some  of  the  cultivated  species  have  variegated 
foliage. 

Blackberry,  Rubus  sps. 

Orange  Rust,  Caeoma  nitens  Schw.  Germination  tests  so  far 
made  show  that  this  rust  on  cultivated  Rubus  villosus  (Gray's 
6th  ed.)  in  this  state  belongs  to  the  short  cycled  form.  This  rust 
was  found  doing  serious  damage  to  a  certain  variety  in  a  plan- 
tation in  Westville  in  1919.  On  the  wild  blackberries,  likewise, 
all  germination  tests  of  the  collections  show  the  rust  to  be  this 
form,  except  one  which  was  long  cycled,  and  later  collections  dis- 
closed the  III  stage  of  Gymnoconia  interstitialis  on  this  same 
plant.     See    "Raspberry"    for  further  details. 

Box,  Buxus  sempervirens  var.  suffruticosa. 

Winter  Injury.  From  time  to  time  during  the  past  years, 
there  have  been  sent  to  the  Station  branches  of  box  in  which  the 
leaves  were  dead,  having  a  yellowish-white  color,  and  complaint 
was  made  that  the  whole  plant  or  part  of  it  was  in  this  condi- 
tion. Search  has  sometimes  revealed  immature  stages  of  some 
fungus  developing  in  these  dead  leaves  or  branches,  but  no  definite 
indication  has  ever  been  found  that  such  a  trouble  was  due  to 
the  attack  of  a  particular  parasite.  Sometimes  we  have  seen 
individual  plants  in  the  nursery  showing  this  trouble,  and  we 
have  wondered  if  it  might  not  be  the  result  of  sun  scorch. 

After  the  severe  winter  of  19 17- 18,  we  saw  so  much  trouble 
of  this  nature  on  box  hedges  that  we  could  not  but  conclude  that 
most,  if  not  all,  of  these  troubles  trace  back  to  severe  winter 
injury  of  the  leaves,  stems  or  roots.  We  saw  one  hedge  at  the 
Whittemore  estate  at  Middlebury  in  the  spring  of  1918,  where 
the  upper  branches  and  leaves  were  all  killed  while  those  below 
were  uninjured.  In  this  case  the  hedge  had  been  protected  dur- 
ing the  winter  by  an  artificial  covering  but  this  did  not  reach  the 
tops  of  the  plants,  with  the  result  that  the  parts  exposed  were 
thus  injured.     Box  is  not  entirely  hardy  so  far  north  as  this  and 


420  CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

in  severe  winters  some  mulch  protection,  either  artificial  or  snow, 
is  usually  needed  to  prevent  winter  injury.  The  winter  of 
1917-18  was  so  severe  that  many  unprotected  hedges  were  ruined. 
Why  in  some  hedges  certain  plants  are  badly  injured  and  others 
escape,  we  cannot  surely  say,  but  this  may  be  due  in  part  to  the 
immaturity  or  the  weaker  condition  of  those  affected. 

Butternut,  Juglans  cinerea. 
Staghead,  Melanconium  oblongutn  Berk.  We  have  not  made 
personal  observations  on  this  fungus  but  have  had  it  called  to 
our  attention  by  Dr.  A.  H.  Graves  who  has  made  a  study  of  it 
in  this  and  adjacent  states.  He  holds  the  view  that  it  is  largely 
responsible  for  the  dead  limbs  so  frequently  seen  on  butternuts, 
and  finally  for  the  stag-headed  appearance  of  the  trees  due  to 
the  death  of  the  tops.  A  discussion  of  it  by  Dr.  Graves  appeared 
in  Mycologia  n  :  111-13,  in  May,  1919. 

Cabbage,  Brassica  oleracea. 

Black  Leg,  Phoma  lingam  (Tode)  Desm.  (P.  oleracea  Sacc.) 
Plate  XXXVI,  b.  We  have  found  this  disease  only  twice  in  this 
state  and  then  under  conditions  that  were  very  unfavorable  to 
the  cabbage  plants.  It  was  first  called  to  our  attention  about  the 
middle  of  November,  1918,  at  the  D.  L.  Clarke  &  Sons'  farm  at 
Milford.  Cabbage  plants  had  been  set  out  very  late  in  their  field 
during  dry  weather.  The  plants  used  had  been  kept  too  long 
in  the  seed  bed,  and  so  were  over-sized  being  long  and  spindling. 
They  were  dropped  in  a  furrow,  watered  and  then  set  in  by 
tramping  the  earth  around  them  with  hoe  and  foot.  The  plants 
as  a  whole  did  very  poorly,  many  died  and  others  failed  to  make 
much  of  a  growth,  so  that  about  90%  were  failures.  When  seen 
by  us  the  stem  underground  and  partly  above  was  badly  withered, 
or  decayed  in  many  cases,  as  shown  in  the  illustration.  The 
fruiting  pustules  of  the  Phoma  could  be  seen  on  most  of  the 
stems,  but  on  others  the  fungus  was  not  evident.  The  same  fall 
at  the  Experiment  Station  farm  at  Mt.  Carmel,  we  found  a  few 
freak  plants  in  the  club-root  experiments  that  showed  the  same 
trouble. 

The  disease  was  first  called  prominently  to  the  attention  of 
cabbage   growers   in   this   country  by   Manns    (Ohio  Agr.   Exp. 


DISEASES    OF    CABBAGE.  421 

Sta.  Bull.  228:276-90.)  of  Ohio  in  1911.  It  seems  to  be  a 
trouble  that  starts  in  the  seed  bed  but  becomes  most  serious  and 
conspicuous  after  transplanting  in  the  field.  The  disease  starts 
on  the  stem  as  a  white  sunken  area,  usually  near  the  junction  of 
a  leaf  petiole,  eventually  forms  serious  cankers  or  girdled  areas, 
invaded  by  bacteria,  etc.,  and  becomes  black  in  color,  hence 
the  common  name  of  "black  leg."  The  fruiting  pustules  are 
easily  made  out  in  the  infected  areas  as  small  black  dots.  The 
spores  are  hyaline,  oval  to  oblong  and  chiefly  3.5-5/*  by  1.5/A-2/X. 
More  recent  investigations  (Wise.  Agr.  Exp.  Sta.  Res.  Bull.  38:  6. 
1915.)  show  that  Phoma  oleracea  Sacc,  as  it  is  called  by  Manns, 
is  a  synonym  of  Phoma  lingam  (Tode)  Desm. 

Cabbage,  Chinese,  Brassica  pekinensis. 

Leaf  Mold,  Alternaria  Brassicae  var.  macrospora  Sacc.  This 
fungus  forms  small,  rounded,  blackish,  zoned  spots  on  the  leaves. 
We  noted  it,  in  1916,  from  the  Station's  farm  at  Mt.  Carmel, 
as  "quite  bad  on  some  varieties."  Apparently  no  specimens  were 
saved  so  nothing  further  can  be  said  of  it. 

Leaf  Spot,  Cercosporella  albo-maculans  (Ell.  &  Ev.)  Sacc. 
This  forms  conspicuous  greyish  spots,  with  a  more  or  less  dis- 
tinct border,  that  are  from  a  quarter  to  half  an  inch  in  diameter. 
In  dried  specimens  some  of  these  spots  retain  a  more  greenish 
color  than  the  rest  of  the  leaf.  Our  specimens  were  collected  on 
Aug.  30,  19 1 7,  at  the  Station's  Mt.  Carmel  farm.  So  far  as  we 
have  learned,  the  fungus  has  not  been  reported  before  on  this 
host,  at  least  under  this  name.  We  have  had  considerable  trouble 
in  identifying  it  because  from  the  dried  specimens  it  is  quite  diffi- 
cult to  determine  how  the  spores  are  borne. 

Alternately  we  have  considered  it  under  the  genera  Cercospora, 
Cylindrosporium  and  Cercosporella,  since  species  on  Brassica  are 
described  under  each  of  these  that  fit  our  specimens  fairly  well, 
especially  as  regards  the  spots  and  appearance  of  the  spores. 
Cercospora  brassicicola  P.  Henn,  described  in  1905  from  Japan 
on  Brassica  sinensis,  however,  seems  not  to  be  the  same  since 
the  hyphae  bearing  the  hyaline  spores  (40-80/x  long)  are  said  to 
be  dark  colored  and  20-25/x  long.  We  could  find  no  such  definite 
hyphae  associated  with  the  spores.  If  the  author  has  mistaken 
other  hyphae  of  saprophytic  species  that  rarely  occur  on  old  spots, 


42  2         CONNECTICUT    EXPERIMENT    STATION   BULLETIN   222. 

we  may  have  what  he  has  described  but  we  have  no  specimens 
for  comparison. 

Cylindrosporium  Brassicae  Faut.  &  Roum.  (Rev.  Myc.  13:81. 
1891.)  seems  to  fit  our  specimens  even  better  as  the  spores  are 
said  to  be  80-120^  long  (forma  Napi,  however,  in  Roum.  Fungi 
sel.  no.  6727,  only  40-80,11)  but  they  are  enclosed  in  the  paren- 
chyma. Our  study  of  these  dried  specimens  (Roum.  Fungi,  sel. 
nos.  5679,  6727,  7318)  leads  us  to  believe  that  the  writers  were 
misled  in  their  conclusions  as  to  the  origin  of  the  spores  and  that 
they  are  really  borne  on  the  outside  on  short  hyphae  as  in  Cer- 
cosporella.  Perhaps  further  study  of  fresh  specimens  from 
France  is  needed  to  definitely  prove  this  point.  This  name  ante- 
dates any  of  the  others. 

Cercosporella  albo-maculans  (E.  &  Ev.)  Sacc.,  originally  de- 
scribed as  a  Cercospora  (Cercosporella)  on  Brassica  campestris 
from  California  (Proc.  Phil.  Acad. :  378.  1894.)  was  placed 
definitely  under  Cercosporella  by  Saccardo  (Syll.  Fung.  11 :  606.) 
because  the  hyphae  (8-12/x  by  2fx)  bearing  the  spores  were  de- 
cribed  as  hyaline.  The  spores  are  given  as  40-6^1  by  2-2. 5/a. 
Except  for  this  somewhat  smaller  size  of  the  spores  the  descrip- 
tion agrees  very  well  with  our  specimens.  These  latter  we  find 
to  vary  from  50-105^  (chiefly  65-90/1,)  by  2.5-3/x.  They  are  hya- 
line, straight  or  somewhat  curved  and  septate.  The  septa  are 
more  or  less  evident,  usually  three  being  found,  but  with  staining 
even  four  to  six  can  sometimes  be  made  out.  After  much  ex-1 
animation  we  definitely  determined  that  the  spores  are  borne 
externally  on  very  short,  inconspicuous,  hyaline  hyphae  no  wider 
than  the  spores.  These  may  be  somewhat  grouped  or  isolated, 
and  come  from  the  stoma  or  directly  through  the  epidermis.  As 
the  spores  are  easily  broken  the  size  given  for  them  may  vary 
according  as  one  measures  them  whole  or  broken.  We  have 
seen  a  fragment  of  the  type  of  C.  albo-maculans,  sent  us  from 
the  N.  Y.  Bot.  Garden,  and  found  the  spores  to  vary  from  45-85/*, 
by  2.5-3,0,  and  as  these  measurements  agree  fairly  well  with  those 
from  our  specimens  we  have  adopted  this  name  though  we  have 
small  doubt  as  to  their  identity  with  the  French  specimens  de- 
scribed under  Cylindrosporium. 

Soft  Rot,  Bacillus  carotovorus  Jones.  Plate  XXXVII,  a.  In 
the  summer  of  1918  a  serious  disease  took  off  at  least  ten  per  cent 


DISEASES    OF    CARROTS,    ETC.  423 

of  the  Chinese  cabbage  grown  at  the  Station's  Mt.  Carmel  farm. 
The  outer  leaves  would  wilt,  drop  over,  turn  yellowish  and  finally 
the  whole  plant  would  go  down.  An  examination  showed  that 
the  trouble  was  of  bacterial  origin  and  the  dropping  of  the  leaves 
was  due  to  the  rotting  of  the  tissue  at  the  base  of  the  petiole  and 
in  the  stem.  When  cut  lengthwise  through  the  stem,  there  was 
revealed  a  rotting  mass  that  in  time  became  hollowed  out  as 
shown  in  the  photo.  Sometimes  the  rot  finally  extended  up  the 
mid  rib  and  even  into  the  leaf  blade.  The  wet  season  may  have 
favored  this  trouble  since  the  cabbage  was  grown  on  soil  not  in 
this  crop  before  and  very  little  manure  was  used;  however,  the 
rot  was  not  very  prevalent  either  the  year  before  or  after  1918, 
although  1919  was  even  more  moist  than  1918.  The  variety 
called  Wong  Bok  seems  to  have  been  most  subject  to  the  rot. 

While  we  made  no  special  bacteriological  study  of  the  rot, 
it  was  so  similar  to  the  ordinary  soft  rot  of  cabbage  and  other 
vegetables  previously  recorded  from  this  state,  that  we  have  little 
doubt  that  the  usual  soft  rot  organism  was  responsible  for  the 
trouble.  Recently  Brown  and  Harvey  (Phytop.  10:81-90.  Fe. 
1920.)  have  described  a  similar  bacterial  rot  of  Chinese  cabbage 
and  have  noted  besides  the  rot  a  spotting  of  the  leaves  due  to  the 
same  cause.  They  think,  however,  that,  while  the  soft  rot  is 
due  to  different  bacteria,  the  trouble  really  starts  through  in- 
vasion of  the  bundles  by  Psendomonas  campestris,  the  black  rot 
organism  of  cabbage,  etc. 

Carrot,  Daucus  Carota. 
Drop  Rot,  Sclerotinia  Libertiana  Fckl.  Carrots  bought  from 
a  grocery  store  by  the  writer  in  the  winter  of  1919-20  developed, 
on  their  outside,  while  stored  in  the  paper  bag,  a  rot  with  the 
conspicuous  white  mycelium  and  large  black  sclerotia  of  the 
above  fungus.  We  have  found  the  same  fungus  causing  drop 
of  lettuce  and  parsley  in  the  greenhouse  and  dampening-off  of 
seedling  beets  in  hot  beds  (Rep.  1908 :  860,  863,  868.)  A  similar 
fungus  of  doubtful  identity  has  been  reported  by  us  as  causing 
a  rot  of  stored  cabbage  (Rep.  191 5  :  428.). 

Celery,  Apium  grceueolens. 
Root  Rot,  Pythium  deBaryanum  Hesse.     Mr.  E.  B.  Hall  of 
Middletown  in  September,  19 15,  sent  us  specimens  of  celery  hav- 


424         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

ing  stunted  roots  more  or  less  rotted  off.  An  examination  of 
these  revealed  the  oospores  of  a  Pythium-like  fungus  in  the  tis- 
sues. We  did  not  determine  the  fungus  more  definitely  at  the 
time,  but  our  recent  study  of  a  variety  of  similar  troubles  led  us 
to  re-examine  the  celery  specimens  and  decide  that  the  fungus 
was  Pythium  deBaryanum.  In  size  and  general  appearance  the 
oogonia  and  oospores  are  the  same  as  those  found  in  the  Spinach 
trouble,  q.  v.,  discussed  elsewhere.  In  these  old  dry  ropts  of 
celery,  however,  the  oogonia  have  become  thicker  and  wrinkled 
somewhat  as  shown  in  Plate  LVI,  5.  Very  similar  wrinkling 
however,  is  developed  in  the  older  artificial  cultures  of  this 
Pythium  when  dried  out,  as  shown  in  Plate  LVI,  8. 

Complaint  was  made  of  serious  injury  to  the  celery  but  whether 
or  not  this  fungus  was  the  chief  cause  could  not  be  determined 
from  the  specimens  received,  as  there  was  also  a  bacterial  rot  of 
the  stems  present,  in  some  plants.  In  Aug.,  1918,  we  had  called 
to  our  attention  a  root  rot  of  Golden  Self-Blanching  celery  on  the 
farm  of  W.  G.  Griswold  at  Wethersheld.  This  was  so  far  ad-1 
vanced  that  the  primary  cause  was  not  determined  though 
Fusarium  and  bacteria  were  at  least  subsequent  agents.  A  care- 
ful search  for  Pythium,  however,  was  not  made.  It  seems  quite 
probable,  however,  that  Pythium,  deBaryanum  may  often  be  the 
starting  point  of  such  root  and  stem  rots. 

Crinkle.  Plate  XXXVII,  b.  The  illustration  shows  the  con- 
trast between  a  normal  leaf  and  one  with  the  crinkle.  This  trouble 
was  called  to  the  writer's  attention,  the  last  of  August,  19 18,  by 
Mr.  H.  D.  Peters  of  Highwood.  He  said  the  trouble  appeared 
rather  suddenly  in  his  celery  field  and  that  the  same  seed  had  not 
shown  it  the  year  before.  At  the  time  of  our  examination  the 
plants  seemed  to  be  outgrowing  the  trouble,  as  the  newest  leaves 
did  not  show  it  to  any  extent.  Crinkle  develops  on  the  leaves  as 
numerous  small  puckers  or  larger  folds  as  if  the  lower  surface 
had  grown  faster  than  the  upper.  Sometimes  the  segments  of  the 
crinkled  leaves  are  much  narrower  than  those  of  the  normal  leaves. 
Occasionally  the  color  of  the  leaf  is  a  lighter  green  but  the  gen- 
eral appearance  is  not  like  that  of  mosaic. 

Evidently  the  trouble  is  developed  in  the  young  growing  leaf 
and  not  after  it  is  matured.  No  signs  of  lice  were  present  and 
the  folding  was  toward  the  upper  surface  rather  than  the  lower, 


DISEASES    OF    CORN.  425 

the  way  lice  normally  injure  the  leaves.  When  the  plants  were 
set  out  early  in  July  the  weather  was  rather  dry,  they  had  not 
been  watered,  and  their  first  leaves  showed  no  crinkling.  It 
seems  probable  since  the  central  leaves  showed  the  trouble  most 
conspicuously  that  it  was  caused  by  a  rather  sudden  change  from 
the  dry  to  the  wet  weather  that  followed  with  abnormally  fast 
growth  compared  with  that  previously  made,  resulting  in  faster 
cell  development  on  the  lower  side  and  the  crinkling.  In  time 
the  plants  become  acclimated  to  the  change  with  a  gradual  re- 
turn to  the  normal  type  of  growth.  Sanford  White  (see  Plate 
XXXVII)  was  the  variety  that  showed  the  trouble  by  far  the  most 
conspicuously  though  it  was  seen  somewhat  on  Salzer's  Early 
Bleaching. 

Corn,  Zea  Mays. 

Anthracnose,  Collet otrichum  graminicolum  (Cesati)  Wilson. 
The  disease  shows  on  the  leaves  of  this  host,  at  first,  as  small 
oval  or  elliptical  spots  containing  more  or  less  evident  fruiting 
pustules.  If  numerous  spots  occur,  the  intervening  tissues  are 
soon  killed  so  that  elongated  irregular,  brownish  areas  run  length- 
wise of  the  leaf  obscuring  the  smaller  spots,  and  the  tissue  may 
become  more  generally  invaded.  The  setae  are  prominent  on  the 
fruiting  pustules  and  are  blackish  straight  spines  about  6  to  8/x 
wide  at  the  base  and  60  to  120/x  long.  The  spores  are  hyaline, 
occasionally  straight  but  chiefly  decidedly  curved  and  broadest 
near  the  center  tapering  to  a  decided  point  at  the  free  end.  They 
vary  from  24-30^  by  5-6/x.  We  have  found  this  fungus  in  this 
state  twice,  collecting  it  once  in  July,  1919,  on  leaves  of  Golden 
Bantam  sweet  corn  at  the  Frank  Beach  farm  in  Woodmont. 
Here  the  fungus  occurred  as  a  parasite  but  did  not  seem  to  be 
causing  any  very  conspicuous  damage,  being  confined  largely  to 
the  lower  smaller  leaves  that  sooner  or  later  die  anyway.  The 
other  collection,  made  on  Aug.  24,  1918,  was  on  the  stalks  of 
sweet  corn  from  the  same  general  neighborhood.  The  stalks  had 
been  collected  for  the  Fusarium  root  rot  mentioned  later,  and 
were  kept  for  some  time  in  paper  bags  where  the  Collet  otrichum 
probably  developed  as  a  saprophyte. 

This  fungus  was  first  presented  in  detail  from  this  country  by 
Selby  and  Manns  (Ohio  Agr.  Exp,  Sta.  Bull.  203:187-211. 
1909.).     Manns  described  it  as  a  new  species,   C.   cereale,  and 


426  CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

found  it  was  causing  more  or  less  injury  to  various  cereals  and 
grasses,  being  especially  bad  on  wheat  and  rye,  since  it  attacked 
the  heads  and  caused  withering  of  the  grain.  He  found  it  on 
the  leaves,  heads,  stems  and  roots  of  its  different  hosts,  but  he  did 
not  include  corn  among  these.  Later  Wilson  (Phytop.  4:  106- 
112.  Ap.  1914.)  made  a  special  study  of  the  nomenclature  of  the 
fungus  and  decided  it  was  an  old  species  that  had  received  about 
a  dozen  specific  names  in  the  past  and  he  adopted  the  one  given 
here  as  the  authentic  name.  He  gives  Zea  Mays  as  a  host,  in 
fact  the  earliest  collection  in  1852  from  Italy  being  in  part  on  it. 
He  also  lists  it  on  this  host  from  Connecticut,  New  Jersey,  S. 
Carolina  and  W.  Virginia  in  the  United  States.  The  citation  on 
Zea  Mays  from  Conn.,  collected  by  Rorer,  apparently  is  intended 
for  Sorghum,  vulgare,  since  we  have  it  in  the  Station's  herbarium 
on  this,  and  Wilson  credits  it  to  Sorghum  only  from  this  state 
in  the  main  part  of  his  paper. 

We  have  not  seen  any  reference  in  literature  where  the  fungus 
was  claimed  to  be  an  active  parasite  of  corn,  most  of  the  collec- 
tions apparently  having  been  made  on  the  dead  stalks.  While 
the  size  of  the  spores  as  found  by  us  on  corn  are  larger  than  those 
given  by  Manns,  they  are  not  larger  than  found  by  Wilson  on 
some  of  the  hosts  and  are  similar  in  appearance  and  size  to  those 
found  in  the  Rorer  specimen  on  Sorghum  (Conn.  Rep.  1903: 
358.).  On  this  latter  host,  however,  the  spotting  is  much  more 
conspicuous  being  very  decided  reddish-brown  on  the  green 
leaves.  It  is  commonly  known  as  Colletotrichum  line 0 la  Cda. 
on  this  host. 

Purple  Fungus,  Monascus  purpureus  Went.  This  fungus 
was  isolated  in  Dec,  19 16,  from  New  Milford  corn  silage  sent 
by  L.  W.  Marsh  who  thought  that  the  silage  was  causing  the 
cattle  fed  on  it  to  scour.  Later  he  came  to  the  conclusion  that 
that  was  not  the  cause  of  the  trouble.  An  examination  of  the 
silage  showed  many  of  the  corn  fragments  of  a  decided  reddish- 
purple  color  and  on  these  by  close  examination  a  moldy  growth  of 
this  fungus  in  fruiting  condition  was  found. 

The  only  reference  we  have  found  where  this  fungus  was  susj 
pected  of  having  caused  injury  is  in  Pammel's  Manual  of  Poison- 
ous Plants,  p.  247,  where  he  says :  "The  family  Monascaceae 
contains  one  fungus  which  has  been  found  in  mouldy  corn  and 
silage  in  Iowa,  the  Monascus  purpureus  Went.     *     *     *     The 


DISEASES    OF    CORN.  427 

coloring  matter  from  M.  purpureus,  known  as  'ang-quac,'  is  used 
in  Eastern  Asia  as  a  pigment,  being  produced  by  the  growth  of 
the  fungus  on  rice.  *  *  *  Dr.  Buchanan  found  this  species 
in  spoiled  corn  silage,  which  was  responsible  for  the  death  of 
several  horses  in  Iowa.  This  species  possibly  has  been  the  cause 
of  the  disease,  this  fungus  occurring  only  where  air  had  access 
to  the  silage." 

Concerning  the  coloring  matter  produced  by  the  fungus  Lafar 
(Tech.  Myc.  2:10.  Salter  trans.)  says:  "To  impart  a  red 
colour  to  rice  wine,  to  various  spirituous  liquors,  bread,  cakes, 
and  to  the  fish  held  in  such  high  esteem  (under  the  name  of 
Macassar  or  red  fish)  in  the  Malay  archipelago,  the  Chinese  em- 
ploy a  colouring  matter  extracted  from  a  red  Hyphomyces,  which 
they  cultivate  on  boiled  rice.  The  fungus  grows  with  vigor  on 
this  medium,  and  imparts  thereto  a  red  coloration ;  and  the  dried 
cultures,  to  which  a  preservative  addition  of  arsenic  and  mustard 
oil  is  made  at  the  time  of  preparation,  form  an  article  of  com- 
merce under  the  name  Ang-Khak.  C.  Went,  has  named  this 
fungus  Monascus  purpureus." 

This  commercial  use  would  indicate  that  the  fungus  was  at 
least  not  a  very  poisonous  species  and  it  is  probably  entirely 
harmless.  Even  when  silage  does  produce  illness  in  cattle  the 
real  cause  of  the  trouble  is  quite  an  open  question,  indigestibility, 
bacteria  and  various  fungi  all  coming  in  for  consideration.  Ap- 
parently as  yet  no  organism  has  been  isolated  and  fed  directly, 
producing  similar  trouble,  to  prove  its  connection. 

Root  and  Stalk  Rot,  Gibberella  Saubinetii  (Mont.)  Sacc.  In 
August,  1918,  in  company  with  Dr.  Hoffer  of  the  Indiana  Station, 
we  examined  fields  of  sweet  corn,  grown  for  seed,  in  the  towns 
of  Orange  and  Milford,  to  determine  if  the  Fusarium  root  and 
stalk  rot,  so  serious  in  the  sweet  corn  fields  in  Indiana,  was  pres- 
ent here.  Connecticut  supplies  much  of  the  seed  of  sweet  corn 
grown  for  the  canneries  in  the  west.  We  found  this  trouble  in 
small  amounts  in  various  fields  of  such  varieties  as  Crosby,  Ever- 
green, Howling  Mob,  Country  Gentleman  and  Golden  Bantam. 
It  was  only  in  a  single  field  of  the  last  variety,  however,  that  the 
trouble  was  conspicuous  enough  to  attract  serious  attention,  as 
about  5%  of  the  stalks  here  were  injured.  As  shown  to  us  by 
Dr.  Hoffer,  the  trouble  may  start  from  the  seed  as  a  primary 


428         CONNECTICUT    EXPERIMENT   STATION    BULLETIN    222. 

infection,  or  it  may  possibly  get  into  the  young  plant  later  through 
injuries  of  the  roots.  In  time  the  roots  are  more  or  less  rotted 
and  the  lower  portion  of  the  stalk  invaded.  By  cutting  stalks 
lengthwise  from  the  base  up,  the  infection  is  shown  by  the  dis- 
colored and  diseased  tissues  at  the  nodes  for  a  shorter  or  longer 
distance  according  to  the  progress  of  the  fungus  upward.  The 
lower  leaves  die  prematurely  and  the  stalk  is  often  barren,  espe- 
cially in  the  west,  and  is  easily  blown  or  broken  over.  The 
trouble  was  seen  again  in  1919  on  sweet  corn,  but  as  yet  we  have 
not  looked  for  it  on  field  corn  where  it  probably  also  occurs. 

While  we  have  made  no  particular  study  of  the  cause  of  the 
disease  we  do  not  doubt  that  it  is  sometimes  carried  in  the  seeds, 
apparently  through  secondary  infections  according  to  Hoffer. 
However,  we  should  judge,  since  it  is  not  a  very  serious  trouble 
here,  that  the  infected  soils  of  the  west  were  more  a  source  of 
infection  there  than  Connecticut  seed.  We  shall  speak  more  of 
this  matter,  however,  under  "Poor  Seed." 

Hoffer,  Johnson  and  Atanasoff  (Journ.  Agr.  Res.  14:611-12. 
23S.  1918.)  have  recently  proved  the  identity  c"  the  Fusarium 
of  corn  root  rot  in  the  west  to  the  Fusarium  causing  scab  of  wheat, 
etc.,  which  is  so  prominent  in  that  region,  and  have  con- 
nected these  with  a  mature  stage  belonging  to  the  genus 
Gibberella.  This  stage  has  also  been  found  on  old  corn  stalks 
recently  in  Connecticut  fields.  The  ascospores  of  this  are  hyaline, 
four-celled,  straight  or  slightly  curved  and  chiefly  24-30/*  long  by 
5-6/x,  wide.  Ellis  issued  (N.  A.  F.  no.  81,  under  the  name  of 
Nectria  (Gibbera)  pulicaris  Fr.)  what  appears  from  our  speci- 
mens to  be  a  different  thing  on  old  corn  stalks. 

On  one  of  our  specimens  we  also  found  Diplodia  macrospora 
Earle,  fruiting  abundantly.  What  connection,  if  any,  this 
fungus  may  have  with  the  root  rot  we  do  not  know.  Diplodia 
Zeae  (Schw.)  Lev.  is  reported  as  a  serious  disease  of  corn  in 
Illinois  (111.  Agr.  Sta.  Bull.  133.)  and  Farlow  and  Seymour 
(Host  Index:  156.)  give  it  as  a  synonym  of  Gibberella  Saubinetii 
Sacc. 

Yearly  rotation  of  corn,  care  being  used  not  to  follow  wheat  or 
rye,  and  the  use  only  of  healthy  vigorous  seed,  are  methods  for 
limiting  this  trouble  to  minimum  injury. 

Root  Rot,  Phytophthora  cactorum  ,(Cohn  &  Leb.)   Schroet. 


DISEASES    OF    CORN.  429 

There  were  various  complaints  in  1919  of  corn  not  doing  well, 
and  the  cause  was  not  always  evident  from  the  information  and 
specimens  received.  Some  of  the  trouble  may  have  been  due  to 
the  Fusarium  already  mentioned,  or  to  the  leaf  blight,  Helmintho- 
sporium  turcicum,  which  killed  the  leaves  as  if  by  a  frost,  espe- 
cially in  late  planted  sweet  corn.  In  other  cases  apparently  neither 
of  these  fungi  was  the  responsible  agent.  An  unusual  case  was 
called  to  our  attention  late  in  the  fall  by  County  Agent  Southwick 
of  Hartford  who  sent  us  corn  stubble  for  examination  and  wrote 
as  follows : — 

"I  got  them  from  John  Cannon  who  lives  in  North  Granby.  This  par- 
ticular field  raised  a  good  crop  of  corn  last  year  but  had  no  other  fertili- 
zation this  year  than  a  thousand  pounds,  I  believe,  of  a  3-10-0  fertilizer. 
The  corn  was  backward  early  in  the  season,  and  on  two  adjacent  fields  as 
well  as  part  of  this  field  cottonseed  meal  was  applied  during  the  summer. 
Wherever  the  cottonseed  meal  was  used  the  corn  seemed  to  recover  and 
made  very  satisfactory  growth.  This  particular  field,  however,  never  made 
very  much  growth  and  was  about  the  size  of  pop  corn  although  it  should 
have  been  good-sized  yellow  flint.  Mr.  Cannon  says  that  when  cultivating 
the  corn  it  was  easy  to  pull  the  whole  plant  out,  as  the  roots  seemed  to  be 
decayed,  particularly  in  the  center. 

"I  noticed  in  pv^.Hng  up  this  stubble  that  some  of  the  first  roots  had  ap- 
parently disappeared  and  that  secondary  roots,  although  small  in  size,  had 
developed.  The  application  of  cottonseed  meal  could  be  determined  right 
up  to  the  last  row  of  corn,  because  in  this  field  it  was  impossible  to  pull 
out  the  stubble  where  cottonseed  meal  was  used,  but  the  next  row  to  it 
was  like  the  specimens  I  send.  I  thought  at  first  perhaps  the  fertilizer 
might  have  contained  some  borax,  but  nothing  on  the  enclosed  tag  seems 
to  warrant  such  an  idea.  Whatever  the  trouble  was  the  cottonseed  meal 
seemed  to  give  the  corn  a  new  start  so  that  a  reasonable  crop  was  secured." 

It  was  of  course  too  late  for  us  to  tell  from  the  specimens 
sent  the  actual  cause  of  the  trouble,  but  we  ran  across  a  fungus 
that  possibly  may  have  had  some  bearing  on  it,  and  as  we  had 
never  seen  it  before  on  corn,  we  have  thought  it  worth  while 
mentioning  even  if  it  should  finally  prove  to  be  merely  a  sapro- 
phyte. In  the  pith  of  the  stubble  when  cut  across  we  found  in 
the  vicinity  of  the  nodes  the  oospores  of  a  fungus,  see  Plate 
LVI,  1,  more  or  less  abundant.  As  there  were  no  other  stages 
with  these  oospores,  and  as  no  cultures  were  obtained,  we  were 
not  sure  at  first  whether  they  belonged  to  a  species  of  Pythium 
or  Phytophthora.  Pythium  deBaryanum  has  been  reported  as 
dampening-off  corn  seedlings  (Fischer,  Die  Pilze  i4:405.)  but 
the  oospores  we  found  are  too  large  for  that  species,  and  are  en- 
veloped too  closely  by  the  oogonium;  besides  there  was  a  good 
stand  of  corn  in  the  field.     The  oogonia  varied  from  21-33/i  but 


43°         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

chiefly  from  24-30^  and  the  oospores  from  18-29/x  but  chiefly  from 
22-27^.  The  walls  of  the  oogonia  and  oospores  were  hyaline, 
and  those  of  the  latter  were  quite  thick  (2.5-4.5//,.)  As  a  rule 
the  oogonia  enveloped  the  oospores  rather  closely  and  likewise 
the  spores  agree  fairly  well  with  those  of  Phytophthora  cactorum 
in  other  respects,  though  the  cell  wall  appears  to  be  thicker  than 
usual  on  spores  in  artificial  cultures. 

Infection  experiments  with  the  culture  of  Phytophthora  cac- 
torum, obtained  from  Pear,  were  not  very  successful  on  corn 
seedlings  either  in  Petrie  dishes  or  in  soil  in  crocks.  We  did, 
however,  in  the  latter  get  one  or  two  seeds  that  showed  oospores 
developed  in  them  and  a  slight  invasion  of  the  main  stem  of  the 
seedling.  We  have  observed  a  number  of  root  rots  of  different 
plants,  especially  in  1919,  that  were  caused  by  Phytophthora  or 
Pythium,  and  these  we  have  discussed  further  under  Pea,  q.  v. 

Albinism,  or  Striped  Chlorosis.  Cases  are  not  rare  in  both 
field  and  sweet  corn  where  the  young  plants  instead  of  being 
normally  green  have  a  whitish  or  yellowish-white  color,  or  have 
similar  elongated  bands  running  lengthwise  of  the  leaves  sepa- 
rated by  the  normal  green  tissues.  The  more  complete  albinos 
never  grow  to  large  plants,  and  even  the  others  are  often  some- 
what stunted  and  may  not  mature  seed.  In  1919  several  cases 
of  the  striped  chlorosis  were  observed  in  Golden  Bantam  Sweet 
corn  in  the  writer's  garden  and  on  a  similar  specimen  of  field 
corn  sent  to  the  station  by  G.  D.  Stone  from  Windham  County. 

Dr.  Jones  of  this  Station  has  grown  experimentally  several 
types  of  such  corn  and  finds  that  when  seed  is  matured  the 
trouble  is  perpetuated  more  or  less  definitely  as  is  the  case  with 
a  number  of  our  variegated  plants  cultivated  for  ornamental  pur-1 
poses.  Just  what  prevents  the  development  of  chlorophyll  in 
certain  portions  of  the  leaf  and  not  elsewhere,  thereby  giving  rise 
to  this  peculiar  striping,  is  not  known.  Davis  (la.  Acad.  Sci. 
24:459-60.)  in  1917  conducted  some  experiments  with  chlorotic 
corn  in  Iowa  that  seem  to  show  that  this  trouble  is  not  com- 
municated by  handling  or  inoculation  as  is  the  mosaic  of  tobacco. 

Pellucid  Spots.  Plate  XXXVIII,  a.  The  trouble  shown  in  the 
photograph  reproduced  here  was  called  to  our  attention  during 
the  summer  of  19 19.  In  June  at  Milford,  Dr.  Britton's  men 
collected  the  first  specimens   from  which  the  photograph  was 


DISEASES    OF    CORN.  43 x 

made;  and  in  July  even  more  striking  specimens  were  received 
from  A.  B.  Case  of  West  Granby.  Dr.  Britton  was  not  able 
to  identify  the  trouble  as  one  caused  by  sucking  insects,  though 
it  has  somewhat  that  appearance.  Neither  did  the  writer  in  the 
fresh  specimens  find  any  fungus  or  bacterial  agent  as  a  probable 
cause.  We  place  it  here  for  the  present  as  an  indefinite  physio- 
logical trouble.  Later,  in  the  dried  herbarium  material,  sections 
showed  some  mycelium  in  the  tissues  but  whether  of  a  sapro- 
phytic or  parasitic  character  could  not  be  determined. 

The  pellucid,  semi-watery,  more  or  less  zoned  spots  have 
somewhat  the  appearance  of  a  bacterial  trouble.  In  some  speci- 
mens these  spots  are  half  an  inch  long  and  very  numerous  so  that 
the  intervening  tissue  is  killed  or  the  spots  run  together  in- 
definitely. When  first  formed  in  the  otherwise  healthy  leaf,  they 
are  quite  striking  in  appearance.  Usually  there  is  a  minute  spot 
at  the  center  which  is  apparently  the  point  of  entrance  or  start- 
ing point  of  the  trouble.  Mr.  Case  wrote:  "The  dead  stalks 
like  sample  are  scattered  over  the  field,  occasionally  a  whole  hill 
infected,  with  good  corn  all  around  it,  but  usually  only  one  stalk 
affected  in  the  hill.  There  is  one  spot  in  the  piece,  however, 
covering  two  square  rods,  where  nearly  all  the  corn  is  affected. 
The  corn  was  all  fertilized  alike." 

Poor  Seed.  In  1917  corn,  field  and  sweet,  over  much  of  the 
United  States  was  of  such  poor  quality  that  it  was  difficult  to 
obtain  seed  of  sufficiently  high  germination  for  the  1918  crop. 
While  this  was  partly  true  of  the  Connecticut  seed  corn,  ap- 
parently the  corn  here  was  not  so  severely  hurt  as  in  most  other 
states.  So  that  there  was  an  unusual  demand,  from  this  state, 
for  good  field  corn  for  seed  purposes.  Germination  tests 
showed  great  variations  in  the  corn,  due  in  part  to  injury  from 
the  early  frosts  in  the  fall  before  the  corn  was  thoroughly 
ripened,  and  in  part  to  the  poor  care  given  in  drying  and  stor- 
ing afterwards.  The  severe  winter  of  1919-20  also  produced 
somewhat  similar  injury  but  to  a  less  degree.  There  is  no  ques- 
tion that,  where  corn  is  grown  for  seed  purposes,  as  is  con- 
siderable of  the  sweet  corn  in  this  state,  more  attention  should 
be  given  to  having  it  properly  matured,  dried  and  stored  to  avoid 
the  injury  that  comes  with  cold  weather.  Much  corn  is  stored 
in  open  corn  cribs  and   great  variation  in  germination   of  this 


43 2         CONNECTICUT   EXPERIMENT    STATION    BULLETIN    222. 

corn,  after  severe  winters,  is  sometimes  shown.  Thoroughly 
dried  corn  or  corn  stored  in  warmer  buildings  does  not  seem  to 
suffer  so  much. 

Frost-injured  corn  usually  develops  wrinkles  in  the  skin,  that 
are  quite  visible  to  the  naked  eye.  On  germinating  in  the  seed 
testers,  this  poor  corn  is  also  apt  to  become  more  or  less  moldy 
with  a  variety  of  saprophytic  molds,  much  as  does  the  Fusarium 
infested  seed  as  shown  by  Hoffer.  There  is  no  doubt  that  such 
seed  even  if  it  does  germinate  will  not  give  as  complete  or  vigor- 
ous a  final  stand  in  the  field  as  perfect  seed.  On  the  other  hand 
it  does  not  appear  that  the  Fusarium  is  primarily  responsible  for 
the  poor  seed  of  19 19  so  that  we  are  not  dealing  with  a  serious 
field  parasite  that  might  be  harder  to  control  than  poor  seed 
due  to  improper  conditions  of  harvesting  and  storing. 

Cotoneaster,  Cotoneaster  horizontalis . 
Red  Canker,  Tubercularia  vulgaris  Tode.  This  fungus  was 
abundant  on  some  dead  stems  sent  us  in  Sept.,  1916,  by  the  Elm 
City  Nursery  Co.,  from  Westville.  Presumably  the  fungus 
followed  winter  injury,  as  it  seems  to  be  more  of  a  saprophyte 
than  a  parasite.  We  have  seen  it  a  number  of  times  on  trees 
winter-injured,  especially  on  nursery  trees  not  strictly  hardy  in 
this  climate. 

Cucumber,  Cucumis  sativus. 
Angular  Leaf  Spot,  Bacterium  lachrymans  Sm.  &  Bryan. 
This  disease  shows  as  evident  angular  spots  on  the  leaves  as 
if  water  soaked.  These  at  first  are  semi-transparent,  but  later 
are  more  opaque,  reddish-brown,  dead  areas  from  which  the  tis- 
sues easily  drop  out.  The  bacteria  also  are  said  to  cause  a  soft 
rot  of  the  leaf  petioles  and  young  vines,  and  from  small  watery 
spots  on  the  surface  of  the  fruit  Burger  believes  there  develops 
a  soft  rot  in  the  interior.  This  disease  was  sent  us  once  or 
twice  from  Indiana  some  years  ago,  but  we  have  only  one  col- 
lection on  cucumber  from  Connecticut  in  the  herbarium.  This 
was  found  on  the  leaves  at  Milford  in  June,  1918.  Our  im- 
pression is  that  we  have  seen  it  at  other  times,  but  did  not  defi- 
nitely identify  it  or  collect  specimens.  However,  we  did  collect 
specimens  on  musk-melons  many  years  before  this. 


DISEASES    OF    BLACK    CURRANT.  433 

There  is  some  question  as  to  who  first  mentioned  this  trouble. 
So  far  as  we  have  determined,  it  seems  to  have  been  first  de- 
scribed in  a  popular  way  in  1894  by  Halsted  (N.  J.  Agr.  Exp. 
Sta.  Rep.  1893:354-5.).  He  found  it  on  musk-melons  and 
reproduced  a  photograph  of  an  infected  leaf,  but  gave  no  sci- 
entific name  to  the  bacterium  producing  the  trouble.  The  writer 
found  the  disease  first  in  Connecticut  on  the  same  host  in  1902, 
and  briefly  mentioned  it  in  his  Reports  (1903:  331.  1904:  346.) 
under  the  Bacterial  Wilt  disease  with  which  we  thought  it 
might  possibly  be  connected.  It  was  collected  at  Southington, 
New  Haven,  Montowese,  and  seemed  to  be  not  uncommon  in 
1902  and  1903,  but  we  have  not  collected  it  since.  Burger 
(Phytopath.  3:169-70.)  in  1913  was  apparently  the  first  to 
make  cultures  and  give  a  scientific  description  of  the  organism, 
which  he  placed  under  the  genus  Pseudomonas,  but  he  gave  no 
specific  name.  More  recently,  Dec,  191 5,  Smith  and  Bryan 
(Journ.  Agr.  Res.  5:465-76.)  gave  a  comprehensive  account  of 
the  organism,  which  they  call  Bacterium  lachrymans.  These 
authors  believe  they  studied  the  same  leaf  disease  but  concluded 
that  Burger  had  a  different  organism  in  the  soft  rot  of  the  fruit. 
It  is  quite  possible  that  this  organism  opens  the  way  for  decay  of 
the  fruit  by  the  ordinary  soft  rot  bacteria.  Some  authorities 
would  consider  Bacterium  lachrymans  as  a  Pseudomonas,  as  it 
has  polar  flagella. 

Currant,  Black,  Ribes  nigrum. 

Leaf  Spot,  Septoria  Ribis  Desm.  This  shows  on  the  leaves 
as  small,  angular,  brownish  spots  with  a  purplish  border.  The 
very  minute,  fruiting  conceptacles  are  embedded  as  black  dots  in 
these.  The  linear  spores  are  curved,  hyaline,  and  chiefly  45^  by 
I/a  in  size.  The  same  fungus  has  been  previously  reported  by 
us  on  red  currants  and  gooseberries.  The  specimens  on  the 
black  currant  reported  here  were  collected  by  the  writer  at  the 
Nathan  Hale  homestead  at  Coventry,  in  June,  1917. 

Rust,  Aecidium  Grossulariae  (P.)  Schum.  This  was  collected 
on  escaped  black  currants  in  North  Stonington,  June  20,  19 19,  by 
Mr.  Stoddard  of  this  department.  It  occurred  on  both  the  fruit 
and  leaves.  This  was  not  the  first  collection  in  the  state,  how- 
ever, as  we  have  specimens  in  the  herbarium  on  t/e  sarre  '     V: 


434         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

made  by  Thaxter  at  Green's  Farms  in  1889,  and  by  Filley,  near 
Bridgeport,  in  1917.  It  has  been  reported  before  on  cultivated 
gooseberries,  but  not  on  cultivated  red  currants,  though  it  is 
quite  common  on  various  wild  species  of  Ribes  in  the  state. 

Currant,  Flowering,  Ribes  odoratum. 

Anthracnose,  Glomerella  cingulata  (Ston.)  Sp.  &  v.  Schr. 
The  Gloeosporium  stage  of  this  fungus  was  found  on  the  fruit  of 
the  flowering  currant  in  a  farm  yard  between  Meriden  and  Mid- 
dlefield,  June  21,  19 17,  by  the  writer.  The  fruiting  stage  showed 
as  numerous  pinkish  pustules  on  the  half  ripened  berries.  The 
spores  were  chiefly  12-15/*,  by  4-5/A.  Apparently  this  fungus  has 
not  been  reported,  at  least  frequently,  on  this  host.  Saccardo 
described  a  species,  Gloeosporium  tubercvdarioides,  as  occurring 
on  the  leaves,  but  this,  because  of  its  wider  spores,  seems  to  be 
different  from  our  species  which  we  have  also  previously  re- 
ported on  the  fruit  of  the  red  currant. 

Blister  Rust,  Cronartium  ribicola  Fisch.  Both  the  lemon- 
yellow  dusty  pustules  of  the  II  or  summer  stage  and  the  hair- 
like spore  columns  of  the  III  or  mature  stage  of  this  fungus 
have  been  found  on  the  cultivated  yellow-flowering  or  Missouri 
currant  in  this  state.  This  host  is  especially  subject  to  the  disease, 
being  almost  as  much  so  as  the  black  currant.  The  collections 
were  made  in  each  of  the  years  1916  to  1919.  They  were  chiefly 
from  the  northern  and  eastern  part  of  the  state,  in  quite  a  num- 
ber of  different  localities,  at  least  twelve  being  recorded  in  1916. 

Currant,  Red,  Ribes  vulgare. 
Blister  Rust,  Cronartium  ribicola  Fisch.  We  have  not  re- 
ported the  white  pine  blister  rust  on  this  host  except  incidentally 
in  our  1915  Report,  p.  423,  where  we  noted  that  Spaulding  found 
specimens  near  Meriden.  There  were  only  a  few  sori  on  aban- 
doned bushes  in  the  Middletown  Water  Company's  Plantation  at 
the  Digby  reservoir.  Since  then  many  other  collections  have 
been  made  in  the  state,  the  rust  being  common  on  abandoned  or 
escaped  currants  in  the  woods  in  the  vicinity  of  Norfolk  and 
especially  near  the  woodlands  where  the  Peridermium  stage  on 
white  pines  is  found.  In  19 16  thirty-eight  collections  were  re- 
ported in  twenty-six  different  towns  or  localities,  and  in  19 17  an 


DISEASES   OF   FIR,   ETC.  435 

even  larger  number  of  collections  were  made  but  mostly  in  the 
same  localities.  Since  then  the  collections  have  been  made  each 
year  but  not  to  such  an  extent  as  the  search  has  not  been  so 
thorough.  While  these  localities  reported  are  fairly  well  scat- 
tered over  the  state  they  represent  chiefly  the  northern  and  east- 
ern sections. 

Mottled  Chlorosis.  We  have  occasionally  seen  isolated 
branches  on  currants  where  the  leaves  showed  a  conspicuous 
yellow  mottling  over  the  whole  or  part  of  the  leaves.  This  may 
show  as  numerous  small  bands  following  the  veins  and  enclosing 
equal  angular  areas  of  normal  green  tissue.  The  cause  of  this 
chlorosis  we  do  not  now  know.  Similar  leaves  have  been  seen  on 
isolated  branches  of  apple  trees.  Injury  to  the  leaves  in  their 
very  young  state  by  sucking  insects  or  by  frost  has  been  sug- 
gested as  a  possible  cause. 

Dewberry,  Rubus  sps. 
Orange  Rust,  Caeoma  nitens  Schw.  Germination  tests  seem 
to  indicate  that  all  specimens  of  this  rust  on  wild  species  of 
Rubus  canadensis  in  Connecticut  belong  to  the  short  cycled 
form.  We  have  not  yet  found  this  rust  on  cultivated  dewberries. 
See  Raspberry,  in  this  Report,  for  further  details. 

Fir,  Douglas,  Pseudotsuga  mucronata. 

Grey  Mold,  Botrytis  cinerea  Pers.  We  are  indebted  to  Mr. 
F.  A.  Bartlett  for  calling  to<  our  attention  in  August,  1919,  this 
disease  on  Douglas  Fir  at  the  Rockefeller  Estate,  Greenwich. 
The  fungus  kills  the  young  shoots  of  the  season's  growth,  and 
develops  a  more  or  less  conspicuous  growth  of  the  characteristic 
conidial  stage  on  the  dead  tissues.  The  fungus  occurs  on  a 
variety  of  herbaceous  plants  as  a  parasite  under  moist  conditions. 

This  fungus  has  been  also  reported  as  causing  injury  to  Doug- 
las Fir  in  Germany  by  Tubeuf  (Diseases  of  Plants :  269.  Eng. 
ed.)  who  named  it  Botrytis  Douglasii  but  Smith  (Bot.  Gaz. 
29:403.  1900.)  considered  it  the  species  mentioned  here,  of 
which  B.  vulgaris  is  also  given  by  him  as  a  synonym.  Some 
authors  (See  Duggar's  Fungous  Dis.  Plants:  196.)  consider  B. 
cinerea  as  merely  the  conidial  stage  of  Sclerotinia  Fuckel 
DeBy. 


436         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Gooseberry,  Ribes  sps. 
Blister  Rust,  Cronartium  ribicola  Fisch.  The  blister  rust, 
both  in  its  II  and  III  stages,  has  been  collected  several  times  on 
cultivated  gooseberries  in  the  state  during  the  last  few  years. 
However  it  does  not  occur  so  commonly  or  abundantly  on  this 
host  as  on  the  red  currant,  and  much  less  so  than  on  the  yellow 
or  black  currants.  Even  when  these  other  plants  alongside  of 
it  are  abundantly  infected,  it  may  escape  infection  entirely.  This 
is  probably  only  a  specific  characteristic  of  the  gooseberries  culti- 
vated here,  as  certain  species  of  native  gooseberries,  and  others 
used  in  our  infection  experiments  indoors,  are  easily  and  abund-1 
antly  infected.  Of  the  five  collections  made  on  cultivated  goose- 
berries in  1916  and  1917,  all  were  on  plants  in  the  northern  or 
eastern  part  of  the  state. 

Grape,   Vitis  sps. 

Rot,  Pythium  hydnosporum  (Mont.)  Schroet.  In  August, 
1919,  E.  V.  Parr  of  Clinton  sent  us  grapes  that  were  badly  dis- 
eased. This  was  chiefly  due  to  the  black  rot  fungus  which 
was  very  prominent  that  year,  though  some  injury  was  also 
caused  by  the  grape  berry  moth.  Other  fungi  present  apparently 
followed  as  saprophytes,  of  which  the  Pythium  named  above  was 
the  most  conspicuous.  It  is  a  fungus  that  is  not  reported,  at 
least  prominently,  in  American  literature.  We  have  seen  it  oc- 
casionally developed  in  rotten  potato  tubers,  the  original  host, 
following  injury  by  Phytophthora  infestans,  and  have  also  found 
it  on  pea  roots  (kept  in  water)  injured  by  the  Phytophthora 
cactorum  mentioned  in  this  Report.  On  these  rotting  grapes, 
however,  we  found  it  developed  more  prominently  than  ever 
before. 

The  oospores  in  certain  grapes  were  very  abundant,  in  some 
being  produced  within  the  pycnia  of  the  black  rot  as  if  belong- 
ing there  naturally.  They  were  also  found  in  the  grape  tissues 
and  even  in  the  bodies  of  the  larvae  infesting  them !  The  oogonia 
(see  Plate  LVI,  9)  are  very  striking  because  of  their  fairly  num- 
erous conspicuous  spines.  These  reach  out  to  2-5/x,  beyond  the 
oogonial  wall  and  are  often  quite  sharply  pointed  but  with  age 
they  may  become  blunter  and  less  conspicuous.  The  smooth 
spherical  oospore  is  often  so  closely  enveloped  by  the  oogonium 


DISEASES    OF    GRAPE.  437 

that  this  resembles  one  of  its  coats.  With  age  the  oogonia  are 
tinted  and,  including  the  spines,  measure  from  20-27/A  in  diame- 
ter, while  the  oospores  vary  from  15-20/x  with  their  thick  wall 
from  2.5-3.5/4,.  No  other  stages  were  seen  by  us  and  according 
to  Winter,  who  calls  it  Pythium  artotrogus,  none  have  been  found. 
It  is  now  placed  under  the  sub-genus  Artotrogus  (under  which  it 
was  originally  described  by  Montaigne)  because  of  the  spiny 
oogonia. 

Lightning  Injury.  In  July,  19 18,  we  had  called  to  our  atten- 
tion at  Marlborough,  lightning  injury  of  grapes.  According  to 
the  owner,  Mr.  d'Esopo  of  Hartford,  a  year  or  two  previous 
lightning  had  struck  the  two  wire  trellis  along  which  the  Clinton 
variety  of  grapes  was  trained.  Within  a  day  or  two  all  the 
branches  that  were  attached  to  the  wires  were  dead.  However, 
the  main  stem  was  not  killed  and  new  runners  were  quickly 
developed  from  this,  so  that  at  the  time  we  saw  them  they  were 
as  vigorous  as  ever.  Prof.  Hollister,  who  was  with  us  at  the 
time,  stated  that  he  had  seen  similar  injury  to  grapes  at  Bolton 
Notch. 

Smoke  Injury.  We  were  called  in  September  1919  to  ex- 
amine serious  smoke  injury  to  a  variety  of  plants  in  the  suburbs 
of  New  Haven.  There  was  a  difference  of  opinion  as  to  the 
cause  of  the  injury,  some  claiming  that  h  came  from  an  aluminium 
factory  and  others  from  a  brick  kill  After  our  examination 
of  the  vegetation  in  the  vicinity  of  each,  we  had  no  hesitancy  in 
deciding  that  the  brick  kiln  was  the  responsible  agent.  The  kiln 
was  situated  along  the  railroad,  and  the  smoke  had  been  carj 
ried  in  a  west  southwestern  direction  until  it  struck  against  the 
hillside  of  East  Rock  Park.  From  the  slopes  of  this  going 
toward  the  kiln,  one  could  trace  all  the  way  in  a  direct  line, 
damage  to  a  variety  of  trees,  vines  and  herbs. 

In  the  park  gray  birch,  beech  and  hornbeam  were  the  trees 
most  injured.  Hemlock,  hickory  and  maples  here  showed  the 
least  injury.  However,  in  1910  (Rep.  1909-10:722.)  we  saw 
serious  injury  to  conifers,  especially  young  spruce,  in  this  same 
park  from  another  brick  kiln.  Maple  and  elm  trees,  midway  of 
the  park  and  the  kiln,  showed  the  trouble  more  or  less  promi- 
nently according  to  their  situation.  Part  of  the  injury  to  the 
maples,  however,  may  have  been  due  to  sun  scorch  as  we  are 


438         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

unable  to  tell  these  troubles  apart  from  the  appearance  of  the 
leaves.  Corn,  tomatoes  and  some  trees  and  weeds  near  the  kiln 
were  also  injured.  Grapes  in  a  number  of  the  yards  midway- 
showed  the  trouble  as  conspicuously  as  any  of  the  plants.  Their 
leaves  were  badly  scorched  and  some  of  the  young  twigs  suf- 
fered injury  at  their  base.  The  ripening  fruit  was  insipid  and 
was  dropping  considerably.  The  few  peach  trees  seen  did  not 
seem  to  be  injured,  which  agrees  with  Stone's  statement,  loc.  cit., 
that  this  tree,  with  black  locust  and  Ailanthus,  is  more  immune 
than  most  trees. 

As  we  have  heard  of  injury  to  vegetation  from  at  least  three 
brick  kilns  in  this  state,  it  might  be  well  to  give  here  the  con- 
ditions under  which,  as  we  understand  them,  this  damage  occurs. 

In  the  first  place  the  injury  is  chiefly  due  to  the  sulphur  diox- 
ide in  the  smoke  that  comes  from  coal  in  the  fires  and  particu- 
larly from  the  coal  dust  mixed  with  the  bricks  to  help  burn  them. 
As  these  become  red  hot  it  is  necessary  at  a  certain  time  in  the 
firing  to  lift  the  board  covers  of  the  sheds  to  avoid  fire  and  let 
out  the  heat  and  smoke.  If  this  takes  place  on  a  wet  or  muggy 
day  and  the  smoke  is  driven  toward  the  ground  and  comes  in 
contact  with  the  damp  foliage,  a  burn  results,  probably  due  to 
the  formation  of  sulphurous  or  sulphuric  acid.  If  the  day  is 
fair  and  the  smoke  ascends  no  damage  results.  So  only  occasion- 
ally, when  all  conditions  are  right,  does  injury  to  vegetation  fol- 
low. Smoke  injury  is  not  always  due  to  sulphur  dioxide,  but 
other  gases  and  sedimentary  deposits  sometimes  cause  injury 
in  specific  cases. 

In  our  Report  for  1908  we  mention  briefly  smoke  injury  to 
asparagus  from  a  brick  kiln  and  in  the  present  one  describe  injury 
to  apple  (q.  v.)  by  smoke  from  a  bronze  factory.  Smelters, 
particularly  in  the  western  United  States,  cause  such  great  injury 
that  much  special  investigation  has  been  made  in  recent  years  by 
botanists  and  others.  Hedgecock  (Torr.  12  :  25-30.  1912,  Journ. 
Wash.  Acad.  Sci.  4:70-1.  1914.)  has  briefly  described  such  in- 
jury in  Montana  and  Tennessee.  Bakke  (la.  Agr.  Exp.  Sta.  Bull. 
I45  :  383-409.  19 1 3.)  gives  a  more  detailed  account,  with  refer- 
ences to  literature,  upon  "The  Effect  of  City  Smoke  on  Vege- 
tation," while  Stone  (Mass.  Agr.  Exp.  Sta.  Bull.  170:228-32. 
1916.)  treats  of  the  effect  of  atmospheric  gases  on  shade  trees, 
in  a  popular  manner. 


DISEASES    OF   GRAPE.  439 

Winter  Injury.  The  d'Esopo  vineyard,  previously  mentioned 
under  Lightning  Injury,  is  situated  on  a  high  ridge  in  Marl- 
borough and  is  the  largest  vineyard  in  the  state,  consisting  of 
about  one  hundred  acres.  For  some  years  the  Italians  have 
been  gradually  going  into  growing  grapes  and  this  fruit  is  there- 
fore becoming  more  prominent  while  the  peach  is  becoming  less 
so.  As  comparatively  few  grapes  have  been  grown  here  com- 
mercially, except  in  a  small  way,  the  troubles  of  the  vine  require 
more  notice   than   has   been   given  them   in  the   past. 

We  wish  to  call  attention  here  to  a  very  serious  trouble  that 
developed  'in  this  vineyard,  chiefly  on  Concords,  which  with 
Professor  Hollister  of  Storrs,  we  were  asked  to  investigate.  It 
was  first  noticed  in  the  early  summer  of  19 17  when  the  vines  in 
some  cases  produced  a  scanty  or  sickly  foliage  and  in  a  few 
cases  died  outright.  Mr.  d'Esopo  thought  some  unknown  dis- 
ease was  at  work,  especially  as  in  1918  the  trouble  became  more 
conspicuous.  Our  examination,  made  July  18,  soon  convinced 
us  that  the  trouble  was  entirely  winter  injury,  due  in  part  to  a 
lack  of  snow  mulch  in  19 16- 17,  but  more  particularly  to  the  very 
severe  winter  of  19 17- 18.  The  vines  most  injured  were  on  a 
ridge.  Some  of  these  were  dead,  others  dying,  or  with  more 
or  less  scanty  foliage,  and  some  apparently  in  fair  shape.  We 
found  the  wood  of  the  sickly  vines  to  be  sound,  but  an  exam- 
ination of  the  roots  showed  these  were  injured  and  in  some 
cases,  especially  those  nearest  the  surface  of  the  ground,  partly 
or  entirely  dead.  The  condition  of  the  foliage  above  ground 
corresponded  so  closely  to  the  condition  of  the  roots  beneath  that 
one  could  not  doubt  that  it  resulted  from  this  diseased  condi- 
tion of  the  roots.  There  was  nothing  on  the  roots  to  indicate 
a  parasite  as  the  cause  of  their  death,  one  peculiar  saprophytic 
hyphomycete  on  certain  dead  roots  being  the  only  fungus  seen. 

There  was  no  question  that  winter  injury  was  the  cause  since 
complaints  of  winter  injury  to  fruit  trees  from  these  two  winters, 
especially  the  last,  had  been  greater  than  for  many  years.  Many 
peach  trees  on  this  farm  had  been  killed.  Then,  too,  the  exposed 
high  elevation  of  the  grapes  had  been  favorable  for  such  in- 
jury and  we  had  another  complaint  from  the  neighborhood  of 
Colchester  of  similar  injury  under  such  conditions  although  the 
grapes  in  both  localities  had  received  good  attention. 


44°         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Most  persons  are  likely  to  overlook  winter  as  the  cause  of 
much  injury  to  grapes  since  it  often  does  not  become  manifest 
until  early  summer,  after  the  foliage  has  been  put  forth,  when 
the  leaves  die  quickly  under  the  hot  sun  or  dry  weather  condi- 
tions. The  winter  is  much  harder  on  the  roots  than  on  the 
vines  above  ground.  Often  the  roots  are  dead  or  badly  injured 
when  the  vines  and  buds  are  uninjured,  but  while  the  buds  may 
develop  they  cannot  live,  or  only  a  portion  can  live  if  the  roots 
are  not  too  severely  injured.  In  the  latter  case  good  cultivation 
and  fertilization  early  in  the  season  to  stimulate  new  root  growth 
is  desirable.  Snow  or  other  mulch  of  course  is  helpful  in  pre- 
venting the  trouble.  Wet  spots  and  shallow  soil  are  to  be  avoided 
as  being  more  likely  to  favor  winter  injury.  Selection  of  hardy 
varieties,  where  possible,  is  also  to  be  taken  into  consideration 
although  the  Concord,  more  or  less  subject  to  injury,  is  the 
most  common  variety  grown. 

Hickory,  Carya  sps. 

Connate  Fomes,  Fomes  connatus  (Weinm.)  Gillet.  Plate 
XXXVIII,  b.  This  fungus  is  called  Fomes  populinus  by  Murrill. 
The  specimen  shown  here  was  collected  Nov.  25,  1918,  on  a  liv- 
ing hickory  tree  in  the  woods  between  New  Haven  and  Milford. 
The  bracketed  pilei  in  this  cluster  were  much  larger  than  we 
have  seen  them  on  the  maple,  the  ordinary  host  in  this  state, 
being  4  by  4  by  8  inches.  The  upper  surface  of  the  pileus  is 
whitish,  with  age  becoming  blackish  or  greenish  with  algal  growth 
behind.  The  under  or  fruiting  surface  has  more  of  a  flesh 
color,  the  rather  small  and  thin  pores  often  having  a  satiny  lustre. 
The  pilei  are  irregular,  with  small  shelves  often  growing  into 
the  larger.  The  stratified  pores,  characteristic  of  the  genus,  are 
evident  but  often  irregularly  placed. 

This  species  differs  from  most  of  the  Fomes  found  in  this 
state  by  the  less  woody  and  more  corky  pileus  especially  its  con- 
text. Murrill  (Northern  Polypores :  47.)  says:  "Rather  com- 
mon throughout  on  living  trunks  of  maple  and  certain  other  de- 
ciduous trees,  causing  decay." 

Witches'  Broom.  Plate  XXXVIII,  c.  This  trouble  of  Carya 
ovata  was  first  called  to  our  attention  in  1917  by  Mr.  E.  B.  Harger 
of  Oxford,  Conn.,  and  we  have  seen  specimens  from  his  trees  each 


DISEASES    OF    HORSECHESTNUT.  44 1 

year  since.  Swollen  places  show  on  the  branches  and  from 
these  several  secondary  branches  are  formed  giving  the  witches' 
broom  effect.  The  leaves  drop  off  prematurely,  often  leaving 
the  petioles  still  attached  to  the  limbs.  The  morbid  growth  even- 
tually dies,  killing  the  parts  beyond.  Mr.  Harger  has  observed 
about  a  dozen  hickory  trees  so  affected  on  his  place  and  thinks 
the  trouble  is  spreading  slowly  although  not  many  of  the  branches 
on  a  tree  are  yet  involved. 

We  were  unable  to  find  any  indications  that  this  was  an 
insect  injury  and  very  little  evidence  that  it  was  caused  by  a 
fungus.  No  fruiting  stages  have  yet  been  seen  on  any  of  the 
branches.  Mr.  Stoddard,  in  examining  the  wood  microscopic- 
ally, found  a  little  evidence  of  mycelium  in  one  specimen  but 
was  unable  to  obtain  cultures  of  a  fungus  from  the  tissues  of 
the  morbid  growths.  Of  course  it  is  possible  this  trouble  is 
merely  a  stag-head  growth  developed  through  winter  injury  of 
the  terminal  bud  or  tip  of  the  twigs. 

Honeysuckle,  Hall's,  Lonicera  japonic  a  var.  Halliana. 
Crown  Gall,  Pseudomonas  tumefaciens  (Sm.  &  Towns.) 
Stev.  This  bacterial  disease  was  sent  us  on  the  above  host, 
new  to  the  state,  from  the  Elm  City  Nursery  in  June,  19 18.  It 
was  not  causing  any  great  damage,  showing  as  small  galls  on 
plants  in  storage. 

Horsechestnut,  Aesculus  Hippocastanum. 

Anthracnose,  Glomerella  cingulata  (Ston.)  Sp.  &  v.S.  Plate 
XXXIX,  a.  Specimens  of  this  disease  of  horsechestnut  were 
sent  us  about  the  middle  of  August,  191 7,  by  Mr.  C.  F.  Crosson 
and  a  short  time  later  we  examined  the  tree  from  which  they 
came.  The  tree  was  in  the  yard  of  Mr.  George  Wilcox  at  Meri- 
den.  Many  of  the  leaves  showed  a  bad  scorch-like  injury  and 
were  dropping  prematurely.  Often  only  part  of  the  leaflets  or 
a  portion  of  the  blade  of  a  single  one  showed  the  reddish-brown 
injury,  the  rest  remaining  the  usual  green  color,  as  shown  in  the 
photograph  reproduced  here.  An  examination  of  the  tissues  of 
the  blades,  the  midribs  and  the  petioles  revealed  the  presence  of 
both  the  Gloeosporium  and  asco  stage  of  the  above  fungus. 

So  far  as  we  know  this  is  a  new,  or  at  least  an  unusual,  host 


442         CONNECTICUT   EXPERIMENT   STATION   BULLETIN    222. 

for  this  fungus  as  it  is  not  reported  in  Saccardo's  or  Farlow  & 
Seymour's  Host  Index  or  by  Shear  and  Wood  in  their  bulletin 
on  Glomerella.  The  tree  was  in  a  sickly  condition,  other  than 
from  the  action  of  this  fungus  on  the  leaves,  apparently  due  to 
winter  injury.  Whether  or  not  this  weakened  condition  of  the 
tree  influenced  the  appearance  of  the  anthracnose  on  the  leaves 
we  do  not  know,  but  there  was  no  doubt  that  it  was  occurring 
there  as  an  active  parasite. 

Red  Canker,  Tubercularia  vulgaris  Tode.  Plate  XXXIX,  b. 
This  was  collected  on  the  branches  of  the  winter  injured  tree 
mentioned  above.  The  fruiting  stage  breaks  through  the  bark 
as  numerous,  small,  firm,  pinkish  pustules.  It  seems  to  be  at 
most  a  weak  parasite  and  is  the  conidial  stage  of  Nectria  cinna- 
barina  (Tode)  Fr.,  with  which  it  is  often  associated  but  was 
not  in  these  specimens. 

Winter  Injury.  Besides  the  above  horsechestnut  tree,  which 
showed  dead  branches  and  some  winter  cankers  due  to  the  unusual 
exposure  on  a  terrace  to  the  western  sun,  we  had  specimens  sent 
us  from  Wallingford,  by  Mr.  C.  H.  Brown,  of  a  rather  unusual 
winter  injury.  The  leaves  on  certain  branches  from  this  tree 
developed  later  and  were  much  smaller  than  those  of  the  rest 
of  the  tree.  On  cutting  those  twigs  lengthwise,  the  pith  in  the 
previous  year's  growth  was  found  to  be,  especially  at  the  nodes, 
turning  a  reddish-brown  color.  This  winter  injury  no  doubt 
had  been  sufficient  to  interfere  somewhat  with  the  transference 
of  the  starch,  as  it  was  present  here  but  not  in  the  normally 
white  pith,  with  the  result  that  while  the  leaves  were  put  forth 
they  did  not  reach  their  full  size  through  lack  of  sufficient  food 
for  normal  growth. 

Hydrangea,  Hydrangea  paniculata  var.  grandiflora. 
Chlorosis.  We  know  of  no  variety  of  this  cultivated  plant 
that  is  variegated.  In  a  yard  near  the  Station  is  a  plant  certain 
of  the  leaves  of  which  showed  a  whitish  mottling,  in  the  fall  of 
1916.  Usually  these  small  spots  ran  more  or  less  together  and 
were  situated  in  the  vicinity  of  the  larger  ribs  or  at  the  margin 
of  the  leaves.  The  mottling  was  quite  varied  in  pattern,  in 
one  case  forming  a  nearly  complete,  narrow,  banded  circle  at 
the  apex  of  a  leaf.     In  some  respects  the  trouble  appeared  like 


DISEASES    OF    KOHLRABI,    ETC.  443 

insect  injury  to  the  leaves  when  very  young  which  prevented 
chlorophyll  formation  at  these  spots. 

Kohlrabi,  Brassica  oleracea  var.  caulo-rapa. 
Club  Root,  Plasmodiophora  Brassicae  Wor.  Plate  XXXIX,  c. 
This  slime  mold  disease  of  cruciferous  plants,  showing  on  the 
roots  as  irregular  knobs  or  gall-like  growths  that  eventually 
rot  off,  has  previously  been  reported  by  us  on  Brussels  sprouts, 
cabbage  and  turnips  (both  yellow  and  white)  and  is  recorded 
here  on  radish,  q.  v.  It  was  found  on  the  roots  of  kohlrabi  sent 
the  Station  in  June,  1918.  Club  root  was  unusually  common 
that  year  being  most  frequently  found  on  cabbage,  the  only  host 
on  which  we  have  found  it  causing  very  much  damage  in  the 
state  so  far.  Badly  infected  cabbage  plants  fail  to  grow,  in 
many  cases  turning  yellow  and  dying  prematurely,  or  at  best 
making  small  heads.  While  the  germs  become  established  in 
the  soil  and  infect  plants  each  year,  certain  seasons  seem  to  favor 
their  development  more  than  others.  The  season  of  1918  was 
much  more  favorable  than  that  of   1920. 

Larkspur,  Delphinium  sp. 
Fasciation.  A  specimen  showing  fasciation  of  a  single  fruit- 
ing stem  of  a  cultivated  larkspur  from  the  garden  of  Mrs.  E.  D. 
Driesbach,  Whitneyville,  was  collected  by  Mr.  Stoddard  in  July, 
1919.  The  flattened  two-foot  stem  in  this  case  was  about  half 
an  inch  wide,  or  twice  its  normal  diameter  for  the  entire  length. 
The  upper  half  of  the  stem  was  occupied  by  the  seed  pods  and 
had  a  half  curl  part  way  up.  The  top  was  forked  for  a  short 
distance  but  the  tips  were  not  coiled.     See  Asparagus. 

Lettuce,  Lactuca  sativa. 
Bladdery  Peziza,  Peziza  vesiculosa  Bull.  Specimens  of  this 
fungus  were  sent  us  in  May,  191 8,  by  Mr.  Gordon  J.  Gale,  Gar- 
den Supervisor  of  Bridgeport,  who  found  them  in  a  cold  frame 
of  lettuce.  They  did  no  harm,  except  from  crowding  the  plants, 
as  the  fungus  is  a  saprophyte  developing  only  on  the  humus  in 
the  soil.  This  is  one  of  the  cup  fungi,  occurring  in  thick  clusters 
of  semi-globose  cups  (often  flattened  by  pressure)  which  are 
closed  at  first  but  later  open  by  an  incurved  broad  mouth.  The 
sessile  cups  are  an  inch  or  two  in  diameter. 


444         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Concerning  the  fruiting  receptacles  Hard  (Mushrooms,  Edible 
and  Otherwise :  508.  1908.)  says:  "They  are  found  on  dung 
hills,  hot-beds  or  wherever  the  ground  has  been  strongly  fertil- 
ized and  contains  the  necessary  moisture.  This  is  an  interesting 
plant  and  often  found  in  large  numbers." 

Maple,  Acer  sps. 
Connate  Fomes,  Foines  connatus  (Weinm.)  Gillet.  We  have 
seen  this  species  several  times  on  maples,  especially  on  living 
red  maples  at  both  Woodbridge  and  Union.  It  is  more  or  less 
of  a  parasite,  chiefly  causing  decay  of  the  heart  wood.  Under 
Hickory  it  is  described  more  in  detail. 

Mountain  Ash,  Pyrus  americana. 

Rust,  Roestelia  cornuta  (Pers.)  Fr.  So  far  we  have  found 
this  rust  only  at  Norfolk,  Conn.  We  remember  seeing  speci- 
mens several  years  ago  on  American  mountain  ash  trees  in  the 
golf  grounds  there  and  in  June,  1919,  collected  specimens  of  the 
spermagonial  stage  on  the  same  host  at  the  edge  of  woods  in 
the  same  general  vicinity.  Very  near  these  small  trees,  whose 
leaves  were  rather  abundantly  infected,  we  found  the  III  or 
mature  stage  on  Juniperus  communis.  On  the  mountain  ash  the 
fungus  makes  conspicuous  yellow  spots,  showing  on  both  sides 
of  the  leaves,  with  the  spermagonia  quite  evident  on  the  upper 
and  the  aecia  in  time  appearing  on  the  lower.  This  fungus  is 
a  northern  species,  apparently,  specimens  having  been  sent  us 
from  both  Massachusetts  and  Maine  where  it  seems  to  be  more 
common  than  in  Connecticut. 

Farlow  (Host  Index:  199.)  also  gives  Aecidium  globosum  on 
this  species  of  mountain  ash  and  Kern  (Bull.  N.  Y.  Bot.  Gard. 
7:434.  191 1.),  while  he  lists  six  species  on  Sorbus,  gives  only 
these  two  on  Pyrus  {Sorbus)  americana.  Concerning  the  III 
stage,  Gymno sporangium  cornutum  (Pers.)  Arth.,  Arthur  (Myc. 
1:240.  1909.)  says:  "Telia  on  branches  of  Juniperus  Sibirica 
Burgsd.  were  collected  May  19,  1908,  by  Mr.  F.  D.  Kern  and 
Mr.  E.  Bethel,  at  Palmer  Lake,  Colo.,  and  sown  May  23,  on 
Sorbus  americana,  giving  an  abundance  of  pycnia  June  1,  fol- 
lowed by  numerous  aecia.  *  *  *  Although  the  horn-like 
aecia  of  this  species  are  common  and  often  collected,  this  is  the 
first  time  that  the  telia  have  been  found  in  America."     Thaxter 


DISEASES    OF    OAK,    ETC.  445 

(Farlow  Bibl.  Index:  36.  1905.)  however,  seems  to  think  the 
proper  name  of  the  mature  stage  is  Gymno sporangium  conicum, 
as  he  says.:  "Since  what  is  believed  to  be  the  true  Gymnospo- 
rangium  conicum  D.  C.  occurs  in  New  England  and  northward 
on  Juniperus  communis,  the  citations  of  Aecidium  comutum  on 
Pirus  americana  in  those  regions  probably  refer  to  the  true 
Aecidium  comutum  of  Europe." 

Musk  Melon,  Cucumis  Melo. 

Angular  Leaf   Spot,  Bacterium  lachrymans  Sm.   &  Bryan. 

Although  this  bacterium  was  described  originally  on  cucumbers 

(q.  v.)  there  seems  *to  be  no  reason  for  doubting  that  it  causes 

the  similar  disease  on  musk  melons  mentioned  by  us  in  our  1903 

and  1904  Reports. 

Oak,  Quercus  sps. 

Pink  Rot,  Cephalothecium  roseum  Cda.  This  fungus  was 
brought  us  in  July,  1916,  by  the  entomological  inspectors,  on 
specimens  of  Quercus  rubra  recently  imported  by  a  nursery  from 
Holland.  They  had  just  been  transplanted  and  the  stems  were 
dying,  a  growth  of  the  above  fungus  developing  on  them.  We 
have  little  doubt  that  the  trees  were  injured  by  long  continued 
or  poor  storage  on  ship-board,  perhaps  developing  scald  from 
improper  watering  and  heating,  and  that  this  fungus  came  as  a 
result  and  not  as  the  cause  of  injury.  During  the  war,  shipping 
conditions  were  very  bad  and  many  shiploads  of  plants  were  lost 
or  greatly  injured  because  of  slow  delivery. 

Sulphury  Polypore,  Polyporus  sulphur eus  (Bull.)  Fr.  Plate 
XXXIX,  d.  Large  fruiting  clusters  of  this  fungus  were  found 
on  a  living  oak  shade  tree  at  the  Barnes  Nursery,  Yalesville,  in 
September,  1917.  The  fungus  was  doing  considerable  injury  to 
the  tree,  possibly  having  got  a  start  through  winter  injury  of  the 
bark.  It  is  one  of  the  larger  and  more  attractive  polypores. 
When  young  the  fruiting  brackets  are  quite  compact,  as  shown  in 
the  illustration,  and  are  fleshy  and  moist,  but  with  age  they 
develop  into  more  flattened,  shelf-like,  overlapping  pilei  that  in 
drying  become  corky  and  brittle  but  are  not  so  durable  as  the 
real  woody  kinds.  The  upper  surface  has  a  reddish  or  orange 
color,  and  the  lower,  poroid,  fruiting  surface  a  decided  sulphur 
yellow.  The  flesh  is  white.  It  is  not  uncommon  as  a  sapro- 
phyte. 


446         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Cooke  (Fungoid  Pests  Cult.  Plants:  208:  1906.)  says  of  it: 
"This  large  and  attractive  looking  polypore  is  a  wound  parasite 
on  several  trees  such  as  oak,  alder,  willow,  poplar,  and  even  pear 
and  apple,  as  well  as  larch."  Von  Schrenk  and  Spaulding  (Bur. 
PI.  Ind.  Bull.  149:37.  1909.)  write,  "It  is  widely  distributed 
throughout  the  United  States  and  Canada  and  in  most  of  the 
forest  regions  of  Europe,  where  it  is  regarded  as  a  destructive 
parasite,  both  on  deciduous  trees  and  conifers." 

White  Heart  Rots,  Fomes  igniarius  (L.)  Gill,  and  F.  Ever- 
hartii  (E.  &  G.)  v.  Schr.  &  Spauld.  By  European  authors  the 
first  of  these  large,  perennial,  woody  fungi  has  been  given  the 
common  names  of  False-tinder  fungus  or  Rusty-hoof  Polyporus. 
It  is  not  uncommon  in  this  section  of  the  country  on  various  hard 
woods,  but  so'  far  in  this  state  we  have  seen  it  only  upon  oak  and 
apple,  q.  v.  As  we  have  observed  this  fungus,  it  first  develops 
as  rounded,  smooth,  ferruginous  knobs  on  the  trunks.  In  time 
these  growths  show  a  differentiation  into  upper  and  lower  sur- 
faces, the  upper  becoming  greyish  in  color  and  the  lower  fer- 
ruginous surface  developing  the  small  fruiting  pores ;  the  shape 
now  has  become  somewhat  ungulate  or  even  more  flattened. 
With  age  the  upper  surface  turns  black  and  is  somewhat  zonate 
and  cracked  but  still  with  a  ferruginous,  smooth,  obtuse  margin 
separating  it  from  the  poroid  surface.  The  spores  are  said  to  be 
hyaline  but  we  have  failed  to  find  them  on  the  specimens  we 
have  examined.  The  stuffed  whitish  tubes  also  are  somewhat 
characteristic. 

Von  Schrenk  and  Spaulding  (U.  S.  Bur.  PI.  Ind.  Bull. 
I49:25~37-  I9°9-)  give  a  comprehensive  description  of  the 
fungus  and  its  injuries  in  their  bulletin  on  "Diseases  of  Decidu- 
ous Forest  Trees."  It  is  considered  quite  a  serious  wood  rotting 
fungus,  causing  the  heart  wood  especially  to  become  broken  up 
into  a  whitish  punk,  hence  the  common  name  of  the  disease.  It 
also  injures  the  living  wood  and  bark  slowly.  The  fungus  not 
only  renders  the  wood  unfit  for  timber  but  weakens  the  trees 
so  that  they  are  more  easily  blown  over.  It  is  said  to  gain  en- 
trance through  wounds  and  often  fruits  near  its  point  of 
entrance.  We  noticed  it  for  several  years  on  a  street  tree  of 
Quercus  velutina  in  New  Haven.  Each  year  the  fruiting  bodies 
were  cut  off  but  reappeared,  in  time,  with  the  disease  slowly  ex- 


DISEASES    OF   ONION.  447 

tending  in  the  bark  until  finally  the  tree  was  cut  down  because 
of  the  injury. 

The  second  species  was  originally  described  by  Ellis  and  Gallo- 
way (Journ.  Mys.  5 :'  141.  1889.)  as  Mucronoporus  Everhartii 
and  has  since  been  placed  by  Murrill  under  both  Pyro  poly  poras 
and  Fulvifomes,  but  in  the  opinion  of  the  writer  belongs  better 
under  the  more  comprehensive  genus  Pomes,  characterized  by 
layers  of  fruiting  tubes  formed  in  superimposed  strata  each 
year.  This  species  is  much  like  the  former  in  appearance  and  is 
sometimes  mistaken  for  it  but  the  upper  surface  becomes  more 
cracked  and  rougher  with  age  and  the  strata  of  tubes  are  more 
reddish  without  much  evidence  of  the  white  stuffed  appearance 
and  easily  yield  an  abundance  of  ferruginous  spores.  Von 
Schrenk  and  Spaulding,  loc.  cit.  p.  48,  state  that  the  action  on 
its  host  is  much  the  same  as  that  of  the  other  species.  We  have 
found  it  only  once  in  this  state,  on  a  living  oak  near  Lake 
Congamond  in  June,  1916. 

Onion,  Allium  Cepa. 

During  the  last  five  or  six  years  some  attention  has  been  given 
by  us  to  the  onions  which  are  grown  for  seed  in  this  state. 
This  seed-growing  has  been  quite  an  industry  in  the  past  but  the 
great  uncertainty  of  a  crop,  due  largely  to  the  so-called  "blast," 
has  discouraged  most  farmers  from  growing  onions  in  recent 
years.  In  our  study  of  the  blast  we  have  noted  various  troubles 
and  abnormalities,  mostly  of  a  non-parasitic  nature,  which  we 
briefly  describe  here.     For  Blast  see  Plate  XLII,  a. 

Rust,  Puccinia  Porri  (Sow.)  Wint.  We  reported  (Conn. 
Agr.  Exp.  Sta.  Rep.  1915:438.  1916.)  the  II  stage  of  this 
fungus,  found  on  ^Egyptian  perennial  onions  at  Storrs,  in  19 14. 
We  have  since  collected  it  on  the  same  plants  several  times  but 
the  collection  on  Nov.  17,  1917,  was  the  only  one  where  we 
found  the  III  stage,  thus  completely  establishing  the  identity  of 
the  rust.     Apparently  this  mature  stage  develops  rather  late. 

Yellow  Leg,  Fusarium  and  bacterial  rots  of  bulbs,  etc.  This 
trouble  usually  shows  when  the  onions  are  fully  grown,  but  not 
matured,  by  occasional  stalks  turning  yellow  below  and  finally 
dying  before  fully  maturing  their  seed.  Such  stalks  are  easily 
pulled  from  the  ground,  as  the  roots  have  been  largely  rotted  off. 


448         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Generally  Fusarium  or  bacteria  are  the  cause  of  this  rot  and 
these  may  come  from  the  old  bulbs,  possibly  developing  there 
largely  as  saprophytes.  Damp  weather  and  poor  bulbs  favor  the 
trouble. 

Bastard  Blossom.  Plate  XL,  a.  This  is  a  common  name  ap- 
plied by  growers  to  occasional  abnormal  heads  that  appear  in 
the  field,  the  appearance  of  which  is  well  shown  in  the  illustra- 
tion where  two  such  heads  are  contrasted  with  the  central  normal 
one.  These  heads  have  the  individual  pedicels  more  elongated, 
so  the  flowers  spread  out  in  a  larger  laxer  bunch.  Growers  com-' 
plain  that  little  or  no  seed  is  developed,  so  they  pull  them  up 
when  seen,  but  whether  the  seed  that  is  produced  tends  to  form 
similar  plants  we  do  not  know.  The  reason  little  seed  is  pro- 
duced is  because  the  pistils  are  often  changed  into  foliacious 
structures.  Sometimes  the  heads  fail  to  form  blossoms  at  all, 
but  in  their  place  form  numerous  slender  stem-like  growths  from 
little  bulbils. 

Bulblet  Head.  Plate  XL,  b.  Occasionally  the  plants,  instead 
of  producing  a  blossom  cluster  at  the  end  of  the  stalk,  form 
a  bunch  of  bulblets  in  the  same  place,  as  is  often  seen  in  wild 
species  and  some  cultivated  varieties.  Rarely  we  have  found 
specimens  like  that  shown  in  the  illustration,  where  after  these 
bulblets  were  started  the  stem  continued  on  above  and  also 
formed  a  smaller  flower  cluster.  The  specimen  figured  here  also 
shows  another  trouble  which  we  call  "Goose  Neck." 

Double  Flower  Head.  Plate  XL,  c.  Occasionally  instead  of 
a  single  flower  cluster  on  the  end  of  the  stem  there  may  be 
two,  a  lateral  one  below  the  other.  Usually  these  are  about  the 
same  size  and  but  a  short  distance  apart,  though  we  have  also 
found  specimens  where  the  lower  one  was  much  farther  down 
the  stem  and  quite  small. 

Elongated  Spathe.  Plate  XLI,  b.  Normally  the  flower  head 
is  enclosed  when  young  by  a  small  spathe  that  later  becomes 
ruptured  and  withers  up  at  the  side  as  a  sort  of  bract.  Occasion^ 
ally,  however,  it  is  more  permanent  and  pretentious,  continuing  as 
a  pointed  extension  of  the  stem,  which  the  blossom  finally  forces 
to  one  side,  as  shown  in  the  illustration. 

Goose  Neck.  Plate  XLI,  a.  This  is  a  term  we  have  coined 
for  those  not  infrequent   crooks   in  the  stems   that  develop   all 


DISEASES    OF   ONION.  449 

the  way  from  a  slight  bend  to  a  completely  coiled  turn  or  even 
a  turn  and  a  half,  as  shown  in  one  specimen  in  the  plate.  We 
cannot  be  sure  of  the  cause  of  these  but  suspect  that  during  rapid 
growth  the  stem  is  sometime  bent  to  one  side,  from  one  cause  or 
another,  and  this  produces  turgor  that  results  in  more  rapid 
growth  on  the  opposite  side  and  the  resulting  curvature.  Pos- 
sibly in  pushing  through  the  bulbs  the  stem  is  sometimes  caught 
at  the  tip  and  before  this  is  released  the  stalk  has  made  a  bending 
exit.  The  natural  tendency,  after  the  bending  has  become 
prominent,  is  for  the  tip  to  again  grow  upwards,  hence  many 
half  turns,  bends,  etc. 

Hail  Injury.  Plate  XLI,  c.  We  saw  rather  severe  injury  to  a 
field  of  Southport  White  Globe  seed  onions  in  Milford,  caused 
by  a  hail  storm  on  July  27,  1917.  As  usual  there  soon  showed  on 
the  side  of  the  stalks  from  which  the  storm  came  the  character- 
istic white  spots  or  marks  that  we  have  found  with  hail  injury 
to  tobacco,  q.  v.  Corn  in  an  adjacent  field  also  showed  a  little 
of  a  similar  injury.  Plate  XLI,  c,  shows  three  hail-injured  onion 
stalks,  two  showing  the  injured  sides  exposed  to  the  hail  and  the 
other  with  the  uninjured  side  protected  from  it. 

White  Ring.  Plate  XLII,  b.  This  trouble  shows  as  narrow 
white  rings  or  cracks  extending  more  or  less  completely  around 
the  stem.  They  apparently  start  as  a  small  break  in  the  epidermis 
which  extends  crosswise  around  the  stem  but  whether  gradually 
or  suddenly  we  do  not  know.  These  rings  may  be  single  or 
several  parallel  to  each  other  and  are  always  found  somewhat 
above  the  bulge  on  the  lower  part  of  the  stem.  If  they  extend 
deeply  into  the  tissues  the  stem  often  breaks  off  at  one  of  them. 

At  first  we  thought  that  they  were  the  result  of  insect  injury 
but  finally  decided  that  they  are  growth  cracks.  The  epidermis 
of  the  stem  is  very  thick  and  the  stem  makes  a  rapid  growth  of 
three  or  four  feet  in  a  few  weeks  at  most.  This  stretches  the 
epidermis  greatly,  especially  longitudinally,  with  the  result,  in  our 
opinion,  that  cracks  develop  at  the  place  of  greatest  strain  which 
appears  to  be  above  the  bulge  on  the  stems. 

Under  the  designation  of  "Crack  Neck"  Chapman  has  recently 
described  (Phytopath.  9:532-4.  1919.)  and  illustrated  a  trouble 
of  chrysanthemums  very  similar  to  this.  The  causes  he  states 
as  follows:    "(1)   Very  little  transpiration  takes  place  as  a  re- 


45°         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

suit  of  the  low  air  temperature  and  the  high  humidity,  and  (2) 
the  soil  temperature  remaining  practically  stationary,  the  soil 
having  been  previously  well  supplied  with  moisture ;  and  the 
roots  functioning  normally  in  so  far  as  the  absorption  of  water 
and  solutes  was  concerned.  These  and  similar  conditions  always 
bring  about  abnormal  cell  relations  and  in  consequence  an  ex- 
cessive turgor  is  brought  about  in  some  of  the  cells  with  no 
normal  means  of  regulation,  such  as  occurs  when  the  plants  are 
transpiring  freely,  and  as  a  result  some  of  the  tissues  must  give 
way  to  permit  of  a  return  to  the  normal  condition." 

Pea,  Piswn  sativum. 

Root  Rot,  Phytophthora  cactorum  (Colin  &  Leb.)  Schroet. 
Early  in  July,  1919,  Mr.  A.  N.  Farnham,  a  large  market  gardener 
of  Westville,  sent  to  our  office  samples  of  pea  vines  that  were 
being  killed  by  some  unknown  agent.  The  vines  at  this  time 
were  in  their  prime,  the  first  picking  not  yet  having  been  made. 
The  vines  eventually  turned  yellow  and  wilted  down,  so  that, 
except  for  the  one  or  two  small  early  pickings,  there  was  prac- 
tically no  crop  in  a  field  of  several  acres.  A  visit  to  the  field 
showed  that  the  trouble  started  as  a  root  rot,  but  in  time  the 
stem  also  rotted  somewhat  below  and  both  became  invaded  by 
bacteria,  nematodes,  etc.  Other  fields  in  the  vicinity  showed  the 
same  trouble,  which  had  little  or  nothing  to  do  with  the  manner 
of  fertilization  or  rotation.  Afterward  complaints  came  in  from 
growers  in  Milford,  Waterbury,  Bloomfield  and  Winsted.  The 
trouble  was  also  seen  in  the  writer's  and  in  the  Station's  garden. 
Very  similar  troubles  have  been  caused  in  previous  years  by 
both  a  Fusarium  and  a  Rhizoctonia  fungus.  While  these  may 
have  been  the  cause  of  the  trouble  on  some  vines  this  year,  we 
could  not  find  them  generally  present,  and  so  were  inclined  to 
look  elsewhere  for  the  chief  cause. 

With  many  of  the  specimens  it  was  difficult  to  find,  on  or- 
dinary examination,  any  fungus  apparently  guilty  of  the  trouble. 
Continued  search,  coupled  with  sections  of  the  tissues,  however, 
usually  revealed  the  presence  of  oospores  of  a  phycomycetous 
fungus  more  or  less  prominent  in  certain  of  the  tissues.  This 
was  especially  true  of  the  Farnham  field  where  we  had  the  best 
opportunity  for  studying  the  trouble.  We  finally  came  to  the 
conclusion  that  this   fungus  was  at  least  the  original  agent  in 


DISEASES   OF   PEA.  45 1 

starting  the  trouble  and  that  its  development  might  be  rather 
local  in  the  underground  parts.  It  was  too  late  to  study  the 
disease  in  its  beginning,  but  it  did  not  seem  to  act  like  the  ordinary 
dampening  off  caused  by  Pythium  de  Baryamim,  especially  since 
no  complaints  of  a  poor  stand  were  received.  We  found  the 
oospores,  occasionally  with  attached  antheridia,  chiefly  in  the 
outermost  tissues  which  also  contained  the  prominent  intercellular 
mycelium  that  gave  rise  to  them.  No  signs  of  any  other  stage 
was  found,  and  apparently  the  mycelium  in  later  stages  of  the 
rot  did  not  develop  so  prominently,  being  crowded  out  by  other 
rot  agents. 

The  oogonia  were  chiefly  hyaline  but  with  age  in  the  old 
specimens  became  somewhat  tinted  yellowish-red  and  the  wall 
(i-2/x  thick)  wrinkled.  They  varied  from  24-36/x  but  were 
chiefly  27-33.//,  m  diameter.  The  thick  walled  (2-4/*)  smooth 
oospores  varied  from  20-30^  but  were  chiefly  22-27/*  in  diameter, 
and  from  oval  to  chiefly  subspherical  in  shape.  The  oval  shape 
was  apparently  due  to  pressure  when  formed  within  the  plant 
cells.  When  we  first  tried  to  identify  this  fungus  from  the 
oospores  found  in  the  tissues,  we  were  uncertain  whether  it  was 
a  Pythium  or  a  Phytophthora.  Naturally  Pythium  deBaryanum 
suggested  itself,  but  the  fungus  failed  to  form  any  external 
mycelium  when  specimens  were  placed  in  water.  The  oogonia 
and  oospores  of  P.  deBaryanum  as  seen  by  us  on  Spinach  (q.  v.), 
also  in  a  culture  received  from  Washington  and  as  given  by 
Fischer  (Die  Pilze  i4:404.  oogonia,  21-24/*;  oospores  15-18/x), 
were  considerably  smaller  than  those  found  in  the  pea  roots. 
Furthermore  Fischer  states  that  Hesse  failed  to  infect  Pisum 
with  Pythium  deBaryanum  in  his  infection  experiments.  Atkin- 
son (Corn.  Agr.  Exp.  Sta.  Bull.  94:245.  1895.)  gives  an  ex- 
tended description  of  Pythium  deBaryanum  that  agrees  with  these 
others  but  not  well  with  our  pea  fungus.  On  the  other  hand 
Jones  (Phytoph.  10:67.  Ja-  1920.)  has  recently  published  a 
note  on  pea  blight  in  Wisconsin,  etc.,  occurring  in  1919,  that 
he  attributes  in  part  to  "Pythium  (probably  deBaryanum)." 
Various  references  exist  in  literature  (Tubeuf  and  Smith  Dis. 
Plants,  p.  117;  Zeitschr.  Pflanzenkr.  2:  253.)  to  a  Pythium 
Sadebeckianum,  described  by  Wittmack  from  Germany  in  1892, 
as  causing  serious  root  rot  of  peas  and  lupins.  We  have  not 
seen  the  original  reference  and  have  not  been  able  to  find  any 


45 2         CONNECTICUT   EXPERIMENT    STATION    BULLETIN    222. 

description  of  the  fungus  giving  measurements  of  the  oogonia 
and  oospores.  It  is  possible  that  this  is  the  fungus  we  have 
found  and  that  it  is  quite  distinct  from  P.  deBaryanum. 

On  the  other  hand  the  fact  that  Hesse  failed  to  infect  peas 
with  P.  de  Baryanum,  and  the  absence  of  any  definite  sporangia, 
so  far  as  we  could  determine,  and  the  agreement  in  size  of  the 
oospores  and  oogonia  with  Phytophthora  cactorum,  has  led  us  to 
conclude  that  this  latter  is  the  fungus  that  we  have  been  dealing 
with.  Our  preliminary  infection  experiments  of  peas  in  Petrie 
dishes  and  crocks  with  P.  cactorum  from  Pear  also  indicated  that 
under  certain  conditions  infection  of  the  seeds  and  roots  may 
take  place,  though  apparently  not  so  abundantly  or  seriously  as 
similar  infections  with  Pythium  deBaryanum.  Apparently  mois- 
ture conditions  and  the  stage  of  the  cultures  are  important  factors 
in  the  results. 

Phytophthora  cactorum  seems  to  be  a  soil  fungus  and  is  ac- 
cused of  causing  root  and  stem  rots  in  a  great  variety  of  plants 
in  Europe.  It  was  present  to  an  unusual  degree  in  Connecticut 
in  19 19,  as  shown  by  rotting  pears  and  apples  on  the  ground. 
The  year  was  very  moist  and  favored  this  unusual  development. 
The  injury  to  corn  (q.  v.)  already  mentioned,  and  the  fact  that 
in  1907  we  found  similar  oospores  in  the  roots  of  rotting  sweet 
peas,  also  help  us  to  the  conclusion  that  in  very  wet  situations 
or  moist  years  this  fungus  may  be  responsible  for  more  or  less 
obscure  root  rots  on  a  wider  range  of  hosts  in  this  country  than 
have  yet  been  reported.  It  is  very  desirable  that  cultures  from 
various  plants  be  obtained  for  definite  comparisons  and  inocu- 
lation experiments.  It  is  not  easy,  however,  to  obtain  cultures 
under  conditions  of  rot  as  produced  on  the  pea  vines. 

In  comparing  the  oogonia  and  oospores  of  these  fungi  in  cul- 
tures with  those  found  in  the  rotting  tissues  in  nature,  it  is 
well  to  remember  that  under  the  latter  conditions,  especially  in 
old  dried  specimens,  one  is  liable  to  find  the  walls  more  deeply 
tinted  and  thicker,  and  the  oogonial  walls  often  wrinkled  or 
folded.  These  variations  might  lead  one  to  suppose  they  are 
specific  differences,  when  they  are  merely  due  to  the  different 
conditions  under  which  the  spores  are  produced.  In  Plate  LVI, 
Dr.  McCormick  has  made  drawings  of  different  species  of 
Pythium  and  Phytophthora  cactorum,  as  produced  in  artificial 
cultures  and  as  found  on  various  hosts  in  nature,  in  which  we 


DISEASES    OF    PEA.  453 

have  tried  to  bring  out  specific  differences  and  the  environmental 
variations  in  the  same  species. 

For  further  discussion  of  Phytophthora  and  Pythium  rots  in 
this  Report,  look  under  the  following:  Apple,  Celery,  Corn, 
Grape,  Pear,  Sweet  Pea  and  Spinach. 

Root  Rot,  Fusarium  sp.  Specimens  of  garden  peas  showing 
this  root  and  stem  rot  were  first  received  from  C.  A.  Weatherby 
of  East  Hartford  in  July,  1917,  and  in  June,  1918,  others  were 
sent  by  J.  H.  Taylor  of  Middletown.  The  general  symptons  are 
very  similar  to  those  mentioned  in  the  preceding  trouble.  The 
plants  usually  attain  fair  size  and  may  even  start  to  blossom 
when  they  turn  yellow  and  wither  away.  An  investigation  shows 
that  the  base  of  the  stem  and  roots  have  been  rotted  away  so  that 
the  vines  are  easily  pulled  from  the  ground.  Microscopical  ex- 
amination of  the  tissues  reveals  the  mycelium  of  a  Fusarium 
rather  abundant  and  extending  up  into  the  healthy  tissues.  Some 
microconidia  may  be  found,  but  if  the  specimens  are  placed  in  a 
moist  chamber  usually  an  abundance  of  a  white  or  pinkish  my- 
celium appears  over  the  tissues  with  both  macro-  and  microconidia. 
Besides  the  Phytophthora  and  Fusarium  mentioned  here,  Rhizoc- 
tonia  also  causes  a  similar  trouble.  Wet  weather  plays  a  very 
prominent  part  in  the  development  of  all  these  fungi.  Care  in 
the  use  of  manure,  rotation  and  frequent  cultivation  to  keep  the 
top  soil  dry,  help  to  control  these  troubles. 

Pea  Shrub,  Lespedeza  Sieboldi. 
Fasciation.  This  abnormality  was  called  to  our  attention  by 
Dr.  Britton  who,  while  inspecting  the  Steven  Hoyt  &  Sons' 
Nursery  at  New  Canaan,  in  the  latter  part  of  August,  1917,  found 
a  couple  of  stems  of  a  plant  of  this  Japanese  shrub-like  herb 
that  were  very  abnormally  flattened.  These  or  similar  stems 
were  seen  at  the  same  place  in  May  by  Mr.  Zappe.  They  were 
at  least  18  inches  in  length  and  where  broken  off  were  still 
flattened  so  that  they  may  have  formed  quite  an  extended  flattened 
stem  as  the  plant,  which  grows  in  bunches  from  the  ground, 
sometimes  reaches  a  length  of  six  feet.  Like  other  fasciation 
we  have  seen,  the  leaves  were  scattered  apparently  irregularly 
over  the  stem  and  the  top  was  recurved  or  coiled  for  a  couple 
of  turns.  One  specimen  had  the  usual  bifurcated  coiled  tips  of 
approximately  the  same  size,  while  the  other  had  a  much  smaller 


454         CONNECTICUT    EXPERIMENT    STATION   BULLETIN    222. 

side  branch.  In  each  case  the  two  branches  coiled  to  the  same 
side.  Under  Asparagus  in  this  Report,  pp.  415-17,  we  call  atten- 
tion to  the  similar  fasciation  on  that  and  other  plants. 

Peach,  Prunus  Persica. 

Die  Back,  Valsa  leucostoma  (Pers.)  Fr.  Plate  XLIII,  a. 
This  trouble  was  first  called  to  our  attention  in  1917  by  Mr. 
N.  S.  Piatt  who'  complained  that  it  was  causing  serious  injury  to 
his  orchard  at  West  Haven.  We  have  examined  the  orchard 
several  times  and  have  seen  cankers  of  all  sizes  from  small  dead 
spots  on  the  twigs  to  large  cankers,  on  the  main  branches,  several 
inches  in  diameter  and  the  bark  entirely  gone.  Often  these  dej 
velop  at  the  base  of  a- dead  twig  or  branch  and  are  much  like 
winter  injury  cankers  with  which  we  believe  the  trouble  to  be 
closely  connected.  Mr.  Piatt,  with  more  or  less  success,  has  tried 
to  control  the  trouble  by  carefully  cutting  away  these  cankers 
each  winter. 

At  first  we  thought  the  trouble  might  have  some  connection 
with  the  brown  rot  as  the  cankers  much  resemble  those  described 
by  Jehle  (Phytopath.  3:105-10.  1913.).  We  failed,  however, 
to  isolate  this  fungus  from  the  injured  or  dead  tissue.  After 
some  failures  we  finally  in  1918  succeeded  rather  uniformly  in 
obtaining  cultures  of  the  Cytospora  stage  of  the  Valsa  here 
named  and  later  were  able  to  find  this  conidial  stage  more  or 
less  abundantly  on  the  infected  branches.  Rolfs  (Mo.  St.  Fruit 
Exp.  Sta.  Bull  17:1-101.  1910.)  made  an  elaborate  study  of 
this  trouble  and  its  cause  and  came  to  the  conclusion,  partly 
through  inoculation  experiments,  that  this  fungus  was  largely 
responsible  for  similar  injury  to  peaches  in  Missouri. 

Winter  Injury.  Plate  XLIII,  b,  shows  a  neglected  and  winter 
injured  peach  orchard  at  East  Wallingford.  During  the  severe 
winter  of  19 17- 18  many  trees  were  killed  or  badly  injured.  Our 
experimental  orchard  at  Yalesville,  although  most  of  the  trees 
were  severely  hurt  and  some  killed,  was  saved  by  vigorous  prun-1 
ing  and  liberal  fertilization  with  sodium  nitrate  and  has  since 
made  a  splendid  growth. 

Pear,  Pyrus  communis. 
Downy  Mildew  Rot,  Phytophthora  cactorum  (Cohn  &  Leb.) 
Schroet.     Plate  XLIV,  a.     We  first  found  this  fungus  on  pears 


DISEASES    OF    PEAR.  455 

sent  us  the  last  of  September,  1919,  by  A.  B.  Beers  of  Bridge- 
port. These  pears  had  been  picked  and  stored  but  when  ripen- 
ing started  rotting  apparently  from  the  inside.  This  was  a  soft 
rot,  the  slightly  discolored  and  diseased  tissues  easily  separating 
from  the  healthy  and  forming  darker  or  reddish-brown  areas 
on  the  skin,  with  no  signs  of  any  spore  stage,  as  shown  in  the 
illustration.  The  microscope  revealed  a  non-septate,  prominent, 
laxly  branched  mycelium,  rich  in  oil-like  drops,  running  between 
the  cells.  Sometimes  there  was  a  sidewise  branch  and  occasion- 
ally two  or  three  with  one  taking  the  place  of  the  main  branch 
and  these  varied  in  width  from  3-9/*.  There  was  no  indication 
whatever  of  any  spore  stage.  The  mycelium  was  evidently  of  the 
same  type  as  that  found  in  the  peculiar  rotting  of  stored  apples 
that  were  sent  in  for  examination  in  1918,  brief  mention  of 
which  has  already  been  made  under  Apple  in  this  Report. 

Petrie  dish  cultures  were  easily  obtained  on  oat  agar  and  these 
produced  a  great  abundance  of  oospores  imbedded  in  the 
medium,  but  no  aerial  growth  bearing  conidia  of  any  kind.  We 
were  not  sure  from  this  whether  the  fungus  was  a  Phytophthora 
or  a  Pythium.  However  when  the  fungus  was  transferred  with 
a  bit  of  the  medium  to  water  in  van  Tieghem  cells  the  typical 
conidia  of  Phytophthora  were  produced.  A  study  of  the  cul- 
tures in  both  stages  led  us  to  the  conclusion  that  the  fungus  was 
Phytophthora  cactorum  as  described  by  Rosenbaum  (Corn.  Agr. 
Exp.  Sta.  Bull.  363: 65-106.  1915.).  Later  cultures  made  at 
the  same  time  and  on  the  same  medium,  oat  agar,  from  this 
pear  fungus  and  from  Phytophthora  cactorum  obtained  from 
Wheztel  in  Nov.,  1909  (host  not  given  us  but  possibly  ginseng,) 
grew  exactly  affke.  The  pear  culture  this  time  developed  a  little 
more  prominent  aerial  growth,  in  which  the  conidial  stage  ap- 
peared. In  cultures  we  found  the  oogonia  varying  from  24-36//. 
and  the  oospores  from  21-32/*,  but  the  average  measurements 
were  for  the  former  27-32/1  and  for  the  latter  24-28/*.  The 
appearance  of  the  oogonia  and  oospores  is  shown  in  Plate  LVI,  4. 

After  determining  the  identity  of  the  fungus  we  searched  for 
it  on  the  fallen  fruit  at  the  Station  grounds.  We  were  surprised 
to  find  on  picking  up  the  partially  rotted  pears  showing  no  ex- 
ternal fruiting  stage  that  most  of  these  contained  mycelium  of 
this  fungus.  An  examination  of  the  most  suspicious  apples  on 
the  ground  in  our  orchard  at  Mt.  Carmel  also  gave  similar  re- 


45 6         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

suits.  However,  because  of  the  advanced  stage  of  the  rots  and 
their  exposure  to  various  animal  and  fungous  invasions,  we  were 
not  able  to  separate  the  Phytophthora  in  pure  cultures  from  either 
the  pears  or  apples.  This  experience  leads  us  to  believe  that  the 
fungus  as  a  fruit  rot  is  more  common  in  this  country  than  reports 
would  indicate;  by  this  we  do  not  mean  as  a  serious  rot  of  fruit 
on  the  trees,  but  as  an  important  rot  of  the  fruit  after  it  falls 
to  the  ground.  It  may  be,  however,  that  the  unusual  moist  con- 
ditions of  last  summer  were  responsible  for  its  development  here. 
In  no  case  on  any  of  the  fruit  have  we  found  any  signs  of  a 
fruiting  stage,  so  the  identity  of  the  fungus  is  easily  overlooked. 

We  should  not  be  surprised  from  our  experience  of  1919  with 
a  variety  of  root  rots,  etc.,  if  the  fungus  is  responsible  in  wet 
years  for  more  injuries  than  we  now  know.  Besides  the  hosts 
we  mention  in  this  Report  (apple,  corn,  peas,  pear,  sweet- pea, 
q.  v.)  Rosenbaum,  in  the  reference  already  cited,  gives  the  hosts 
for  this  fungus,  reported  chiefly  from  Europe,  as  follows :  Panax 
quinquefolium,  Cereus  giganteus,  Melocactus  nigrotomentosus, 
Phyllocactus,  Sempervirum,  Fagus,  Acer,  Pinus,  Larix,  Picea. 

An  examination  of  the  literature  showed  that  this  fungus  al- 
ready had  been  reported  from  this  country  on  apples.  Whetzel 
and  Rosenbaum  (Phytopath.  6:89.  Fe.  1916.)  reported  it  from 
New  York  state  as  found  in  July,  191 5.  These  apples  were  on 
a  tree  in  a  garden,  but  were  on  branches  near  the  ground.  They 
also  stated  that  it  was  isolated  in  the  laboratory  from  apples 
purchased  in  the  market  and  give  references  to  its  occurrence 
on  both  apples  and  pears  in  Europe.  They  report,  too,  that 
Osterwalder  found  both  conidia  and  oospores  on  rotted  fruit  in 
Switzerland,  which  is  different  from  our  experience.  Hesler 
(Bu.  PI.  Ind.  PI.  Dis.  Sur.  2:172.  15S.  1918.)  has  since  re- 
ported this  trouble  on  other  varieties  of  apples  from  New  York. 
Very  recently  Giissow  (Phytopath.  10:50.  Ja.  1920.)  reported 
the  fungus  on  pears  in  Nova  Scotia.  So  far  as  we  have  learned, 
our  report  is  the  first  on  this  fruit  in  the  United  States.  Under 
the  title  of  "A  Phytophthora  Rot  of  Pears  and  Apples"  Wor- 
mald  (Ann.  Appl.  Biol.  6:89-100.  D.  1919.)  has  very  recently 
reported  this  same  disease  from  England  and  given  a  detailed 
account  of  it  including  inoculation  experiments  and  references 
to  literature. 


DISEASES    OF    PINE.  457 

We  have  tried  no  inoculation  experiments  yet  with  the  cultures 
obtained  from  the  pear  on  either  apples  or  pears.  However  from 
this  same  culture  we  had  tried  to  infect  20  kinds  of  seedlings 
of  herbaceous  plants  to  prove  its  connection  with  the  root  rots 
that  have  been  reported  on  certain  of  these.  The  results  are 
partially  given  elsewhere  under  a  few  of  these  hosts. 

Winter  Injury  Swellings.  A  trouble,  similar  to  that  shown  on 
apple-twigs  in  Plate  XXXV,  b,  was  found  on  pears  by  the  Stam- 
ford Quality  Seed  Store  in  March  and  by  Miss  Daisy  Ineson 
from  Ansonia  in  April,  1920.  The  swellings  on  the  small  twigs 
were  usually  at  the  end  of  the  preceding  year's  growth  and 
often  at  the  base  of  a  dead  twig  or  where  one  had  been.  They 
were  about  twice  the  normal  diameter  of  the  twig  and  usually 
less  than  an  inch  long.  Cross  sections  showed  the  swelling  due 
to  increase  of  pith  cells  and  to  a  less  extent  of  bark  cells,  with 
more  or  less  irregular  arrangement  of  tissues  which  were  some- 
what blackened. 

The  similarity  of  these  enlargements  to  those  described  by 
Hedgecock  on  apples,  loc.  cit.,  due  to  the  crown  gall  organism, 
led  us  to  believe  at  first  that  these  had  similar  origin.  Specimens 
were  sent  to  Dr.  Smith  who  said  that  they  were  not  so  caused 
and  suggested  winter  injury.  Inoculations  made  by  Dr.  Mc- 
Cormick  on  geranium  stems  with  fragments  of  the  injured  tis- 
sues failed  to  produce  any  suspicious  growth  although  similar 
inoculations  made  at  the  same  time  with  cultures  of  the  crown 
gall,  Pseudomonas,  were  quite  successful.  This  leads  us  to  con- 
clude that  winter  injury,  killing  the  young  growth  of  the  year 
and  slightly  injuring  that  of  the  preceding  year,  caused  the 
latter  to  make  a  morbid  growth  resulting  in  these  enlargements. 

Pine,  Pinus  sps. 

Black  Rot,  Spltaeropsis  Malorum  Berk.  This  is  a  common 
fungus  that  causes  more  or  less  injury  on  apple  twigs  and 
leaves.  We  found  it  on  the  leaves  of  Pinus  austriaca,  collected 
at  Black  Point,  Niantic,  and  mentioned  later  under  winter  injury 
of  buds.  It  seemed  there  to  be  a  saprophyte,  or  at  best  only  a 
weak  parasite,  the  trouble  being  originally  due  to  winter  injury. 
Hesler  (Corn.  Agr.  Exp.  Sta.  Bull.  379:98.     1916.)  gives  white 


45 8         CONNECTICUT   EXPERIMENT    STATION   BULLETIN   222. 

pine  as  one  of  the  hosts  of  this  stage  of  the  fungus  whose  mature 
form  he  finds  to  be  Physalospora  Cydoniae  Arn. 

Lightning  Injury.  Plate  XLIV,  b.  In  September,  1917,  the 
writer  with  State  Forester  Filley  inspected  a  white  pine  tree  at 
Cornwall  that  had  been  struck  by  lightning  about  a  month  pre- 
viously. It  was  a  beautiful  tall  specimen  standing  by  itself  on 
a  hillside.  The  bolt  had  made  an  evident  crack  in  the  bark 
from  about  two  thirds  the  way  up,  where  the  branches  began, 
to  the  ground  forty  feet  below.  Except  for  this  splitting  and  a 
slight  shattering  of  the  bark,  as  shown  in  the  photograph  taken 
by  Mr.  Filley,  and  a  few  broken  branches,  there  was  no  evident 
injury  to  the  tree.  Even  the  foliage  on  the  broken-off  branches 
was  still  green.  The  injury  was  therefore  mechanical  and  not 
fatal  to  the  cambium,  etc.,  as  in  the  cases  of  lightning  injury 
to  grape  and  tobacco  mentioned  elsewhere  in  this  report. 

Mice  Girdle.  We  saw  serious  injury  to  a  young  plantation 
of  white  pine  on  a  low  spot  in  the  American  Optical  Co.'s  land 
at  Union  in  1918,  and  had  previously  received  specimens  from 
Watertown  and  elsewhere.  During  the  winter  of  1919-20,  mice 
were  also'  said  to  have  seriously  girdled  Scotch  pine  in  some 
plantations.     See  Mice  Girdle  under  Apple. 

Snow  Bend.  Plate  XLIV,  c.  In  the  younger  white  pine  plan- 
tations in  the  vicinity  of  Norfolk,  after  winters  of  heavy  snow 
fall,  the  tops  of  the  pines  have  been  so  long  bent  over  from  the 
weight  of  snow  that  the  injury  causes  more  or  less  permanent 
bends,  as  shown  in  the  illustration. 

Winter  {Bark)  Injury.  Occasionally  on  the  sunny  side  of 
white  pine  trees,  there  are  seen  more  or  less  extended  reddish 
brown  areas,  in  strong  contrast  with  the  greenish  color  of  the 
healthy  bark.  Cutting  these  with  a  knife  shows  that  the  tissues 
are  dead,  at  least  part  way  to  the  wood.  As  fruiting  bodies  are 
not  seen  in  these  areas  and  as  cultures  from  their  tissues  have 
yielded  no  fungous  growth,  they  appear  to  be  merely  local  winter 
cankers.  Often  on  older  stems,  where  the  tissues  are  changing 
from  the  smooth  to  the  rough  bark  type,  numerous  small  spots 
of  similar  color  are  seen  but  these  do  not  usually  reach  in  deep 
enough  to  cause  particular  injury. 

Winter  {Bud)  Injury.  Plate  XLV,  c.  The  writer,  with  Mr. 
Filley,  during  the  summer  of  1918  and  twice  since,  made  examina- 


DISEASES    OF   PINE.  459 

tions  of  injured  Austrian  pines  near  the  shore  in  two  places.  The 
first  called  to  our  attention  was  on  Black  Point,  near  Niantic  at 
the  summer  residence  of  Mr.  A.  H.  Mosle;  the  second  was  at 
the  residence  of  Dr.  Winfield  Ayres  at  Shippan  Point,  near 
Stamford.  In  both  cases  the  trees  were  close  to  the  shore  and 
exposed  to  the  severe  winter  storms.  The  trouble  showed 
prominently  the  following  summer  when  many  of  the  tips  of  the 
branches  failed  to  grow  or  their  buds  opened  and  developed  only 
weakly,  often  dying  later,  as  shown  in  the  illustration.  In  late 
summer  these  injured  and  dead  tips  are  in  strong  contrast  with 
the  healthy  ones  and  are  scattered  more  or  less  over  the  trees. 
The  leaves  at  the  tip  of  the  Austrian  pine  branches  form  in 
winter  a  cup  in  which  frozen  spray  could  be  easily  held,  thereby 
offering  excellent  opportunity  for  winter  injury  of  the  buds  and 
adjacent  tissues. 

A  search  revealed  no  suspicious  insects  as  possible  cause,  and 
the  only  fungus  found,  and  that  sparingly  on  the  oldest  injured 
buds,  was  the  black  rot,  Sphaeropsis  Malorum,  previously  men- 
tioned. The  Austrian  pine  does  not  seem  quite  hardy  for  such 
exposed  places  so  that  each  winter  some  buds  are  injured  but 
that  of  1917-18,  being  exceptionally  severe,  caused  an  unusual 
amount  of  injury.  One  of  the  owners  was  inclined  to  think  the 
trouble  a  contagious  disease,  but  we  have  seen  somewhat  similar 
injury  to  unhardy  pines  in  the  state  plantations  at  Rainbow.  We 
have  never  found  this  trouble  inland  on  Austrian  pines,  but 
specimens  were  sent  us  from  Watch  Hill,  R.  I.,  also  on  the  Sound, 
in  1919,  so  we  have  no  doubt  as  to  its  winter  injury  nature. 

Witches'  Brooms.  We  have  seen  two  types  of  witches'  brooms, 
illustrated  here,  on  pines.  On  the  white  pine  the  broom  took  a 
bushy  shape  due  to  numerous  small  branches  developing  equal 
growth,  with  the  leaves  compactly  massed  together.  (Plate 
XLVI,  a.)  The  other,  XLV,  b,  was  on  a  branch  of  Scotch  pine 
in  a  plantation  at  Union,  where  the  abnormal  growth  was  more 
elongated.  As  this  had  numerous,  stunted,  small  branches  along 
the  sides,  it  possibly  in  time  would  have  developed  similarly  to 
the  other,  which  was  evidently  older.  No  cause  was  found  for 
either  trouble,  though  winter  injury  might  offer  a  plausible 
explanation  in  the  absence  of  any  other. 

Yellozv  Stem-Spot.     Plate  XLV,  a.     On  the  young  branches  of 


460         CONNECTICUT    EXPERIMENT    STATION   BULLETIN    222. 

white  pine  one  or  two  seasons  old,  there  frequently  develop, 
especially  in  the  vicinity  of  Norfolk,  evident  golden  or  yellow  spots 
on  the  green  bark.  These  spots  are  usually  about  a  quarter  to  a 
third  of  an  inch  in  diameter  and  very  frequently  center  from  the 
base  of  a  leaf  bundle  whose  leaves  may  also  be  yellowed  at 
their  base  and  shorter  than  normal.  As  these  spots  resemble 
so  nearly,  in  color,  the  blister-rust  infection  spots  on  the  leaves 
and  occur  most  conspicuously  in  a  region  where  blister-rust  had 
escaped  into  the  woods,  we  thought  that  they  might  be  the  first 
signs  of  stem  infection  by  this  fungus.  Continued  search  of 
microscopic  sections  made  through  such  spots,  however,  has 
uniformly  failed  to  show  any  evidence  of  mycelium.  The  next 
suspicious  agent  was  the  spittle  bug,  as  this  insect  was  quite 
abundant  on  these  young  twigs  in  that  vicinity,  but  as  yet  no 
definite  connection  between  the  two  has  been  shown.  Injury  by 
bending  is  said  to  cause  similar  spots. 

Pine,  Umbrella,  Sciadopitys  verticillata. 
Black  Scurf,  Rhizoctonia  Solani  Kuhn.  The  mycelium  of 
this  fungus  was  found  by  entomological  inspector  Zappe  creeping 
abundantly  over  the  stems  of  young  Japanese  umbrella  pines  just 
imported  from  Holland.  It  had  not  caused  much  injury  however. 
Packing  the  plants  closely  in  a  closed  case  no  doubt  favored  its 
development. 

Pleroma,  Pleroma  splendens. 

Intumescence.  Plate  XLVI,  b.  This  unusual  trouble  on  the 
leaves  of  a  Pleroma  plant  was  sent  to  the  Station  in  Oct.,  1916, 
by  Dr.  F.  H.  Williams  of  Bristol.  Although  he  had  owned  the 
plant  for  twenty  years,  this  malady  had  only  shown  during  the 
last  three  or  four.  During  the  winters  the  plant  was  kept  in  a 
window  on  an  enclosed  stoop,  steam  heated,  and  in  the  summers 
was  planted  outdoors,  usually  in  shade.  As  the  white  fly  had 
troubled  it  the  last  winter,  it  was  cut  back  to  the  roots  when 
taken  out  doors  and  planted  in  the  sun.  It  made  a  fair  new 
growth  outdoors,  with  no  trouble  showing,  and  when  trans- 
ferred indoors  continued  to  grow  rapidly  with  the  intumes- 
cences appearing  in  the  leaves.  Later  formed  leaves,  however, 
did  not  show  the  trouble. 

The  very  small  pimply  outbreaks,  faintly  shown  in  the  illus- 
tration because  of  the  hairy  covering,  were  confined  chiefly  to 


DISEASES    OF    POPLAR.  46t 

the  upper  surface  of  the  leaves  and  were  usually  thickly  placed 
over  the  whole  surface.  They  resembled  somewhat  extraneous 
deposits  since  when  wet  they  had  a  gelatinous-like  appearance. 
Sections  through  the  leaves  showed  that  they  were  formed  by  a 
morbid  growth  of  unusually  elongated  cells.  We  think  the 
trouble  was  due  to  unusual  turgor  brought  about  in  the  develop- 
ing leaves  from  excessive  water  supplied  by  the  roots.  Cutting 
back  the  plants  severely,  planting  them  in  the  sun  outdoors,  and 
then  transferring  them  to  the  partially  shaded  stoop,  with  the 
presence  of  numerous  hairs  on  the  leaves  to  lessen  transpiration, 
all  were  factors  in  upsetting  the  proper  balance  between  water 
supplied  by  the  roots  and  its  transpiration  from  the  leaves. 

Several  American  papers  have  appeared,  most  of  them  re- 
cently, on  intumescence  of  leaves.  Von  Schrenk  (Mo.  Bot. 
Gard.  Rep.  16:125-48.  1905.)  describes  and  figures  intumes- 
cences on  cauliflower  leaves  due  to  various  copper  sprays.  Smith 
(Journ.  Agr.  Res.  8:165-86.  1917.)  similarly  treats  of  intu- 
mescence on  this  same  host  produced  by  various  chemical  vapors. 
Harvey  (Ibid.  15:83-111.  1918.)  relates  where  they  were 
caused  on  cabbage  by  frost.  Wolf  (Ibid.  13  :  253-9.  1918-)  gives 
injury  from  wind-blown  sand  as  an  ultimate  cause  of  such  trouble 
on  cabbage. 

Poplar,  Populus  sps. 
European  Canker,  Dothichiza  populea  Sacc.  &  Briard. 
Plate  XLVII,  a.  This  disease  has  been  well  described  by  Hedge- 
cock  and  Hunt  (Mycol.  8:300-8.  1916.).  It  was  first  called 
definitely  to  our  attention  in  Connecticut  by  F.  A.  Bartlett  (Tree 
Talk  4:76.  1917.)  from  Stamford  in  1917.  We  are  not  sure, 
however,  that  the  canker  trouble  mentioned  in  our  1903  Report, 
p.  347,  was  not  due  to  this  fungus.  In  recent  years  specimens 
have  been  received  from  Stonington,  Hartford,  New  Canaan  and 
New  Haven.  It  is  found  in  nurseries  as  well  as  on  private 
grounds,  and  in  our  experience  seems  to  be  more  or  less  associ- 
ated with  winter  injury.  The  Lombardy  poplar  is  the  most 
common  host  here.  On  smooth  bark  of  smaller  branches  it 
forms  a  brownish  dead  area  with  the  fruiting  stage  evident  as 
small  erumpent  pustules.  On  older  branches  or  the  main  trunks 
quite  evident  cankers,  as  shown  in  the  illustration  here,  may 
develop.     When  these  girdle  the  stem  the  parts  beyond  die. 


462         CONNECTICUT    EXPERIMENT    STATION    BULLETIN   222. 

Potato,  Solatium  tuberosum. 

While  not  as  a  rule  so  serious  as  the  fungous  diseases,  non- 
parasitic troubles  of  the  potato  are  at  least  more  numerous  in  this 
state.  They  are  due  to  a  variety  of  causes  but  chiefly  to  un- 
favorable or  unusual  weather  conditions.  A  few  are  caused  by 
other  environmental  factors ;  some  are  constitutional,  being  in- 
herited from  the  preceding  crop ;  one  or  two  are  somewhat  infec- 
tious. Regarding  the  weather  conditions,  mention  should  be  made 
of  the  year  191 8,  when  an  unusually  large  number  of  these 
troubles  appeared,  due  in  part  to  the  effect  of  the  severe  winter 
of  1917-18  on  the  stored  tubers  and  in  part  to  the  wet-spring, 
dry-summer  weather  that  followed.  In  the  previous  Reports  we 
have  discussed  briefly  a  few  of  these  troubles,  such  as  tip-burn, 
internal  brown  spot,  spray  injury,  etc.,  and  in  the  following 
pages  fifteen  more  are  added  to  this  list. 

Aerial  Tubers.  Plate  XLVII,  b.  Occasionally  there  has  been 
sent  to  the  Station  for  examination  and  explanation  potato  vines 
producing  abnormal  swellings  on  the  stems  above  ground.  In 
such  cases  usually  some  injury  has  occurred  on  the  stem  beneath 
the  ground,  thereby  cutting  off  the  food  material  manufactured 
in  the  leaves  from  being  transferred  to  the  rootstocks  where  it 
is  stored  in  the  tubers.  As  a  result  of  injury  below,  the  material 
is  stored  in  the  stem  above  ground  in  these  unusual  aerial  tubers. 
Injury  to  the  stem  by  the  Rhizoctonia  fungus  is  one  of  the  com- 
mon causes  of  these  monstrosities.  In  both  1916  and  1917  fine 
examples  of  aerial  potatoes  were  reported;  Plate  XLVII,  b,  shows 
some  of  those  found  on  plants  in  a  Yalesville  field  where  the 
injury  was  caused  by  Rhizoctonia.  Orton  (U.  S<.  Dept.  Agr. 
Bull.  64:33.  1914.)  has  described  a  case  of  aerial  tubers  on 
leaf  roll  plants  where  there  was  no  injury  to  the  base  of  the 
plants.  Phloem-necrosis,  no  doubt,  had  its  influence  in  this  case, 
as  the  elaborated  sap  is  carried  down  the  stem  through  the  phloem. 

Black  Heart.  This  trouble,  as  indicated  by  its  name,  shows 
as  a  blackening  of  the  tissues  at  the  center  of  the  tuber.  Often 
this  blackening  is  accompanied  by  large  cavities.  It  has  only 
been  reported  to  us  once  or  twice,  in  recent  years,  from  this  state. 

Bartholomew  (Phytopath.  3:  180-2.  1913.)  found  it  developed 
on  potatoes  shipped  in  heated  cars  and  he  was  able  to  produce  it 
in  the  laboratory   "when  potatoes  taken  in  April  and  May  from 


DISEASES    OF    POTATO.  4^3 

storage  cellars  were  exposed  to  a  temperature  of  about  380  to 
45 °C,  in  an  ordinary  drying  oven  for  from  eighteen  to  forty-eight 
hours." 

Stewart  and  Mix  (N.  Y.  Exp.  Sta.  Bull.  436:  321-62.  1917.), 
who  also  studied  the  trouble,  succeeded  in  producing  it  by  cutting 
down  the  supply  of  oxygen  needed  for  the  slow  changes  that  take 
place  in  the  dormant  tubers.  They  therefore  concluded  that  the 
trouble  results  from  improper  storage  conditions,  such  as  poor 
ventilation  and  piling  the  potatoes  too  deeply  in  bins  and  cars, 
as  well  as  by  too  high  a  storage  temperature. 

Curly  Dwarf.  Plate  XLVIII,  a.  As  indicated  by  the  name  and 
by  the  accompanying  illustration,  this  trouble  applies  to  potato 
plants  of  a  decided  dwarfed  development,  with  curling  and  wrink- 
ling of  the  foliage.  Orton  (loc.  cit.:  37-40.  1914.)  writes: 
"The  stem  and  its  branches,  the  leaf  petioles,  and  even  the  mid- 
ribs and  veins  of  the  leaves  all  tend  to  be  shortened  in  many 
cases  to  a  very  marked  extent,  and  particularly  in  the  upper 
nodes  of  the  plant,  so  that  the  foliage  is  thickly  clustered. 
Typical  curly-dwarf  is  readily  distinguished  from  leaf-roll  by 
the  wrinkled  or  downward  curling  of  the  leaves,  the  normal  color 
of  the  foliage  and  the  firmness  of  the  leaves,  which  do  not  lack 
turgidity." 

We  have  occasionally  found  curly-dwarf  plants  in  potato  fields 
in  this  state,  but  do  not  believe  it  is  as  common  here  as  in  some 
potato  districts.  It  is  an  hereditary  trouble  transmitted  through 
the  tubers.  Quanjer  (Phytopath.  10:35-47.  1920.)  claims  that 
curly-dwarf  is  only  an  extreme  case  of  mosaic. 

Frozen  Tubers.  During  the  winter  of  1917-18,  because  of 
its  severity,  many  potatoes  in  farm  storage  in  this  state  were 
frozen.  Badly  frozen  tubers  soon  rot,  so  they  are  of  no  value. 
Others  only  slightly  hurt  are  often  put  on  the  market.  Such 
tubers  tend  to  darken,  when  cut.  We  believe  that  some  of  the 
unusual  troubles,  such  as  spindling  sprout,  that  developed  in  the 
potato  crops  of  1918  were  due  to  potatoes  so  injured. 

Hollow  Heart.  Plate  XLVIII,  b.  This  is  a  name  applied  to 
potatoes  that  have  a  conspicuous  cavity  in  their  center.  Large 
potatoes,  especially  those  of  certain  varieties  as  Dibble's  Russet, 
are  more  apt  to  develop  such  cavities  than  the  smaller  tubers. 
Usually   the   trouble   appears   in   a   season    favorable    for    rapid 


464         CONNECTICUT    EXPERIMENT    STATION   BULLETIN    222. 

growth,  especially  if  dry  weather  is  followed  by  very  wet.  The 
cracking  of  the  fruit  in  certain  varieties  of  peaches  and  musk 
melons  is  a  similar  phenomenon  in  our  opinion. 

Leaf  Roll.  Plate  XLIX,  a.  This  trouble  is  distinguished  by  a 
decided  upward  roll  of  the  margins  of  the  leaves,  and  often  is 
accompanied  by  more  or  less  color  changes.  The  plants  often 
make  a  fairly  normal  growth  otherwise.  It  is  easily  distinguished 
from  the  work  of  aphids  by  the  upward,  instead  of  the  downward, 
roll  of  the  leaf  margins.  Leaf  roll  has  been  much  studied  in 
Europe  (See  Orton,  loc.  cit.:  18-33.)  and  there  are  various 
opinions  concerning  it.  There  seem  to  be  at  least  two  types,  one 
merely  a  seasonal  trouble  due  to  unfavorable  weather  condi- 
tions, as  too  much  wet  weather  followed  by  dry,  and  another  that 
is  a  constitutional  and  more  serious  trouble.  Most  of  the  roll 
we  have  seen  in  this  state  on  both  potatoes  and  tomatoes  we 
believe  to  be  of  the  former  type*  In  19 18,  however,  in  a  yard 
in  Westville,  we  saw  what  may  have  been  the  second  type.  It 
was  quite  evident  on  Gold  Coin,  but  not  on  other  varieties  grown 
near  by.  True  leaf  roll,  according  to  Quanjer,  is  a  phloem j 
necrosis  trouble  and  is  both  contagious  and  pseudo-hereditary. 

Mosaic.  This  chlorosis  trouble  of  potato  foliage  was  first 
noticed  by  the  writer  in  this  state  in  the  early  summer  of  19 16. 
Both  Green  Mountain  and  Irish  Cobblers,  the  two  varieties 
most  commonly  grown  here,  showed  the  trpuble.  It  was  seen 
again  in  1917  in  several  fields,  but  probably  not  so  prominently 
on  the  whole,  as  in  1916.  In  19 18  it  was  more  prominent  but 
in  1919  it  was  less  evident  than  in  any  of  these  years,  due  appar- 
ently to  favorable  weather  conditions  for  foliage  growth.  The 
leaves  show  a  yellow-green  mottling  and  some  crinkling  of  the 
foliage,  something  like  the  mosaic  of  tobacco  but  usually  not  so 
prominent.  As  the  vines  grow  older  this  mottling  usually  be- 
comes less  rather  than  more  prominent.  Mosaic  tubers  from 
Maine,  furnished  the  writer  by  the  U.  S.  Dept.  of  Agr.  and  planted 
at  Mt.  Carmel  in  1919,  failed  to  show  any  more  signs  of  mosaic 
on  their  leaves  than  did  the  so-called  checks  from  the  same  source. 
The  former,  on  the  other  hand,  were  a  less  thrifty  strain,  as 
shown  by  the  size  of  the  vines,  etc. 

We  have  not  noticed  that  Connecticut  potato  fields  were  very 
materially  affected  as  to  vigor  or  yield  of  tubers,  but  in  Maine 


DISEASES    OF   POTATO.  4^5 

and  some  other  states  where  this  trouble  is  more  prominent,  it 
is  said  that  mosaic  plants  give  smaller  yields.  In  Bermuda 
Wortley  (Rep.  Dir.  Agr.  1914  and  1915.)  reports  this  trouble 
very  bad  on  Bliss  Triumph.  He  found  the  yield  from  mosaic 
tubers  to  be  half  that  from  tubers  of  mosaic  free  plants.  As  a 
result  of  his  investigations  importation  of  seed  stock  into  this 
island  is  regulated  to  guard  against  bringing  in  this  trouble  from 
badly  infected  fields. 

Ouanjer  of  Holland,  loc.  cit.,  and  Schultz  et  al.  of  the  U.  S. 
Dept.  of  Agr.  (Journ.  Agr.  Res.  17:247-73.  1919.)  have  done 
much  work  on  this  disease  and  their  experiments  show  that  it 
is  not  only  a  constitutional  trouble  carried  by  the  tubers,  but  it 
is  contagious  in  the  field.  The  latter  investigator  found  aphids 
as  one  of  the  carriers  of  the  trouble  from  diseased  to  healthy 
plants. 

Net  Necrosis.  Plate  XLIX,  b.  We  have  previously  described 
in  one  of  our  Reports  an  internal  brown  spot  of  potato  tubers 
that  is  somewhat  similar  to  this.  In  net  necrosis,  however,  the 
brownish  diseased  areas  are  smaller  and  more  net-like.  Neither 
is  caused  by  fungi  and  their  nature  is  not  well  understood.  It 
is  thought  by  some  that  net  necrosis  is  connected  with  some  of 
the  other   troubles   described   here. 

Potash  Hunger.  In  1917  and  1918  there  was  some  indica- 
tion that  potatoes  suffered  from  lack  of  potash,  especially  on 
certain  soils  and  where  manure  was  not  used  abundantly.  Such 
plants  are  said  'to  show  more  or  less  bronzing  of  the  foliage  and 
are  apt  to  flop  over  easily  or  turn  yellow  and  die  prematurely 
and  are  subject  to  early  invasion  by  saprophytic  fungi.  It  is 
hard  to  tell,  in  our  opinion,  potash  hunger  from  unbalanced  fer-1 
tilization  or  from  the  drought  injury  described  here  in  detail 
under  Wilt  and  Prematuring,  q.  v. 

Premature  Sprouts.  Plate  L,  a.  Another  trouble  of  potatoes 
reported  as  not  uncommon  in  both  1916  and  1917  was  the 
premature  sprouting  of  the  tubers  before  being  dug.  Usually 
only  occasional  hills  in  the  fields  showed  this  trouble,  so  that 
the  injury  was  not  very  great,  and  the  sprouts  found  were  not 
elongated,  being  something  like  those  shown  in  the  illustration. 
However  we  did  see  cases  in  1917  where  these  sprouts  not  only 
became  elongated  but  appeared  above  ground  and  formed  foliage. 


466         CONNECTICUT    EXPERIMENT   STATION    BULLETIN    222. 

Sometimes  the  sprouts  merely  developed  into  small  secondary 
tubers.  Such  are  sometimes  found  on  sprouting  old  tubers  in 
storage. 

We  are  not  sure  of  the  cause  of  this  premature  sprouting  but 
believe  it  may  be  caused  by  plants  receiving  a  serious  set-back, 
as  by  drought,  before  they  are  fully  matured,  and  then  having  a 
favorable  period  for  growth  start  into  activity  again.  Such  con- 
ditions we  know  will  cause  "knobby"  tubers.  Knobby  tubers 
are  often  found  in  fields  where  tip-burn  or  blight  has  badly  in- 
jured the  vines  but  still  left  them  vigorous  enough  to  respond  to 
a  later  favorable  growing  period. 

Rootstock  Invaded-Tubers.  Plates  L,  b,  LI,  a.  An  occasional 
injury  is  found  in  potato  fields  where  the  rootstocks  of  some 
other  plant  penetrate  the  tubers  themselves.  Nut  grass,  Cyperus 
sp.,  not  infrequently  causes  injury  of  this  kind.  The  most 
serious  injury  of  this  same  nature  we  have  seen  was  in  a  field 
of  Mr.  Arthur  Clark  at  Orange  in  19 17  and  was  caused  by  quack 
grass,  Agropyrum  re  pens.  Here  the  slender  rootstocks  of  the 
grass,  as  shown  in  the  illustration,  not  only  bored  into  many  of 
the  tubers,  but  in  some  cases  went  clear  through  them,  coming  out 
at  the  opposite  end  and  formed  a  leafy  shoot  above  ground.  It 
is  a  question  whether  these  penetrating  rootstocks  receive  any 
nourishment  from  the  potato  tubers.  The  tissues  of  the  two 
plants  evidently  form  no  union,  though  in  some  cases,  short  side 
sucker-like  branches  were  formed.  No  noticeable  injury  of  tis- 
sues in  their  vicinity  was  observed ;  in  fact  the  rootstocks  seemed 
to  force  their  way  through  the  tubers  with  no  special  discolor- 
ation of  the  invaded  tissues.  Such  invaded  tubers  have  no 
market  value. 

Russeted  Tubers.  Plate  LI,  b.  This  name  is  applied  to  tubers 
with  a  thicker  or  rougher  skin.  Certain  varieties  have  a  more 
russeted  skin  than  do  others,  but  under  certain  conditions 
the  skin  in  the  same  variety  may  be  rougher  than  normal.  The 
sample  shown  here  is  an  unusual  or  areated  russeted  type.  It 
came  from  Maine  seed  potatoes  and  probably,  as  in  other  cases, 
was  due  to  some  external  irritant,  like  a  fertilizer,  acting  on  the 
skin  when  quite  young,  and  stimulating  it  to  form  an  unusual 
corky  growth. 

Spindling  Sprout.  Plate  LI,  c.  The  chief  characteristic  of 
this  trouble  is  the  slender  needle-shaped  sprouts  that  appear  in 


DISEASES    OF    POTATO.  467 

place  of  the  normal  lead-pencil  thick  sprouts.  The  trouble  was 
not  uncommon  in  1918  but  we  saw  little  of  it  before  or  since. 
This  leads  to  the  belief  that  it  is  in  some  way  connected  with 
freezing  or  too  cold  storage  of  the  tubers  in  the  preceding  winter. 
Spindling  sprouts  grow  into  very  weak  small  plants  that  yield 
poorly  if  they  survive.  One  grower  in  1918  plowed  up  his 
entire  field  as  worthless.  Stewart  and  Sirrine  (N.  Y.  Agr.  Exp. 
Sta.  Bull.  399:133-43-  1915O  have  studied  this  trouble  rather 
carefully,  and  while  they  do  not  know  the  cause  they  found  home- 
grown seed  developed  the  trouble  much  more  than  northern 
grown,  where  the  trouble  rarely  occurs.  Excessive  heat  and 
drought  are  given  by  them  as  a  possible  cause. 

Wilt  and  Prematuring.  Plate  LI  I,  a.  There  appeared  sud- 
denly, in  1918,  in  southern  Connecticut  an  unusual  trouble  popu- 
larly designated  as  a  blight,  which  was  first  called  to  the  writer's 
attention  on  July  6th  in  a  field  that  had  grown  potatoes  for 
three  years.  In  this  field  a  spot  had  yellowed  up  and  was  dying 
prematurely,  and  the  owner  said  that  he  had  first  noticed  the 
trouble  two  or  three  days  previously.  Later  the  writer  saw  many 
similar  fields  and  received  numerous  complaints.  The  trouble 
seemed  to  be  a  complicated  one  with  indications  that  more  than 
one  factor  entered  into  it.  However,  our  general  conclusion  was 
that  primarily  it  was  not  due  to  fungi  but  rather  to  lack  of  suffi- 
cient moisture  and  food  for  continued  normal  plant  growth. 

The  fields  visited  showed  two  or  three  types  of  the  trouble, 
as  follows :  1 .  A  prematuring  of  the  vines  in  which  the  stem 
and  leaves  gradually  turn  yellow,  the  plant  often  remaining  erect, 
the  leaves  dropping  off  or  dying,  and  finally  the  whole  plant  suc- 
cumbing. 2.  Plants  wilting  and  flopping  over  as  if  the  stem 
had  not  strength  enough  to  support  them.  Parts  normally  green 
and  no  particular  spotting  of  the  stem.  3.  A  bronzing  and 
spotting  more  or  less  of  the  stem ;  plants  lopping  over  somewhat ; 
frequently  the  stem  was  soft  near  the  ground  so  that  it  was  easily 
pinched  together,  as  if  some  fungus  or  borer  had  been  at  work. 

We  carefully  examined  the  stems  above  and  below  the  ground 
in  the  field,  and  cut  many  sections  of  the  stems  in  the  laboratory, 
and  while  occasionally  bacteria  and  fungous  threads  were  seen 
which  might  aid  in  wilting,  and  a  Phoma  that  possibly  might 
cause  rotting,  we  found  no  definite  association  of  these  particular 
agencies  with  the  trouble. 


468         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

The  wilt  first  showed  on  Irish  Cobblers  or  other  early  varieties. 
Irish  Cobblers  and  Green  Mountains  are  the  varieties  most  fre- 
quently planted  in  this  State,  and  are  the  ones  on  which  the 
trouble  appeared  most  prominently.  Dibble's  Russet  was  the  least 
injured  variety  seen.  We  have  since  learned  that  it  is  a  variety 
quite  resistant  to  drought  injury. 

The  time  of  planting  or  maturing  of  the  potatoes  seemed  to 
have  had  considerable  to  do  with  the  appearance  of  the  disease. 
In  other  words,  the  trouble  did  not  develop  until  the  plants  had 
bloomed  and  were  in  that  stage  where  the  foliage  had  made  its 
growth  and  most  of  its  energies  were  used  in  the  formation  of 
tubers.  The  trouble  quite  often  was  very  prominent  on  Irish 
Cobblers  when  Green  Mountains  beside  them  did  not  show  it, 
or  on  Irish  Cobblers  when  near-by  rows  of  the  same  variety 
planted  a  few  days  later  did  not  show  it.  In  time,  however,  both 
the  Green  Mountains  and  the  later  planted  Cobblers  did  have  the 
trouble  when  they  reached  the  right  stage  of  maturity.  One 
farmer  planted  Irish  Cobblers  and  Green  Mountains  on  four 
different  dates,  covering  a  month,  and  the  trouble  appeared  in 
the  fields  and  varieties  in  the  order  of  their  planting  and  maturity, 
being  quite  severe  on  the  earliest  when  just  beginning  to  show 
up  on  the  latest. 

We  saw  many  cases  where  the  trouble  showed  over  a  field  when 
the  vines  under  shade  trees,  especially  apples  which  are  apt  to 
be  within  the  field,  were  still  quite  green  and  unaffected. \  In 
other  cases  where  the  field  was  quite  irregular  the  vines  were  al- 
ways green  in  the  gullies  on  the  lower  portions  where  the  earth 
-was  more  moist  and  got  the  wash  from  the  fertilization.  Invari- 
ably in  fields  with  gravelly  knolls  the  trouble  first  appeared  and 
showed  more  prominently  in  those  spots,  no  matter  what  the 
fertilization.  In  fields  insufficiently  fertilized,  the  trouble  was 
most  pronounced,  especially  if  only  artificial  fertilizers  were  used. 
Fields  that  had  been  heavily  manured,  or  had  a  complete  fer- 
tilizer containing  potash,  did  not  usually  suffer  like  fields  where 
only  a  4-10  fertilizer  was  used.  Fields  of  poor  or  leachy  soil  on 
which  a  4-10  fertilizer  was  used  were  seen  producing  a  fairly 
luxuriant  growth  under  the.  favorable  moist  conditions  of  the 
spring  and  early  summer,  but  going  down  when  this  fertilizer 
had  been  used  up  or  leached  out. 


DISEASES   OF   RASPBERRY,  ETC.  469 

The  lack  of  moisture  had  a  very  important  bearing  on  this 
trouble  and  was  also  shown  by  injury  to  other  plants,  grass 
dying,  and  trees  losing  their  foliage,  from  the  dry  hot  weather 
of  July  21st  to  30th.  The  potato  is  more  subject  to  drought  in- 
jury than  any  of  our  cultivated  crops,  so  naturally  this  was  the 
first  to  show  ill  effects.  Ordinarily  this  is  shown  as  tip-burn  but 
in  1918  the  injury  was  not  so  much  of  this  type  as  in  the  pre- 
maturing  of  the  foliage. 

All  these  facts  led  us  to  the  conclusion  that  lack  of  moisture 
and  in  some  cases  insufficient  plant  food  of  which  lack  of  potash 
was  one  of  the  chief  factors,  were  primarily  responsible  for  most 
of  the  troubles,  rather  than  fungi,  poor  seed,  or  insects,  especially 
lice,  all  of  which  were  attributed  as  the  cause. 

Radish,  Raphanus  sativus. 
Club  Root,  Plasmodiophora  Brassicae  Wor.     This  was  sent 
us  Sept.  20th,  1917,  from  Northford  by  Mr.  Burnham  and  was 
the  first  collection  on  the  radish  from  the  state.     See  Kohlrabi  in 
this  Report. 

Raspberry,  Rubus  sps. 

Orange  Rust,  Gymnoconia  interstitialis  (Schl.)  Lag.  (Puc- 
cinia  Peckiana  Howe) .  Plate  LII,  b.  In  our  1903  Report  under 
Blackberry,  Dewberry  and  Raspberry  we  recorded  the  presence 
of  the  I  stage  (Caeoma  nitens)  of  this  fungus  as  occurring  on 
these  hosts  in  Connecticut.  The  recent  work  of  Kunkel  (Bull. 
Tor.  Bot.  Club.  43 .:  559.  N.  1916.)  however  has  shown  that 
there  are  two  forms  in  this  country  known  under  the  gen- 
eral term  Caeoma  nitens.  One  of  these  germinates  with  a  long 
non-septate  germ  tube,  and  the  other  with  a  short  septate  pro- 
mycelium  producing  sporidia.  Morphologically  the  spores  of  the 
two  cannot  be  distinguished.  The  first  form  Kunkel  calls  the 
long  cycled  because  it  is  the  I  stage  (Caeoma  interstitialis  Schl.) 
of  Gymnoconia  interstitialis,  also  found  in  Europe,  and  the  other 
he  calls  the  short  cycled  since  it  apparently  reproduces  itself 
and  has  no  connection  with  any  other  stage.  This  latter  form 
he  considers  to  be  the  true  Caeoma  nitens  of  Schweinitz.  Arthur 
more  recently  (Bot.  Gaz.  LXIII:5oi.  Je.  1917.)  has  made 
this  latter  form  the  basis  of  a  new  genus  and  placed  it  under 
the  species  Kunkelia  nitens    (Schw.)   Arth.     He  has  made  an 


47°         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222, 

arbitrary  attempt  to  determine  the  specimens  of  the  I  stage  in 
his  herbarium,  placing  them  with  one  or  the  other  of  these 
genera  (Gymnoconia  and  Kunkelia)  chiefly  according  to  the 
part  of  the  country  from  which  they  came. 

Later  still  an  article  by  Atkinson  (Am.  Journ.  Bot.  5 :  79-83. 
F.  19 1 8.)  has  appeared,  in  which  he  advocates  from  his  investi- 
gations and  the  distribution  of  the  two  forms,  that  the  life  cycle 
of  Gymnoconia  Peckiana,  as  he  calls  it,  is  not  definitely  fixed 
so  that  in  the  warm  climate  of  the  south  it  produces  the  short 
cycled  form  and  in  the  cool  climate  of  the  north  the  long  cycled 
form,  and  in  between  sometimes  one  and  sometimes  the  other 
according  to  the  temperature  conditions  of  June  and  July.  This 
interpretation  is  based  largely  on  the  results  of  infecting  raspber- 
ries at  low  temperatures  (under  bell  jar  with  ice)  with  spores  of 
the  short  cycled  form  from  wild  dewberry,  Rubus  canadensis  as 
called  in  our  paper,  and  producing  the  telial  stage  of  the  long 
cycled  form.  He  thinks  that  under  these  cool  conditions  the  short 
cycled  form  instead  of  forming  a  promycelium  with  sporidia, 
really  formed  the  germ  tube  characteristic  of  the  long  cycled  form. 

For  some  years  we  have  believed  that  the  orange  rust  of 
Connecticut,  found  most  commonly  on  wild  dewberry,  was  dis- 
tinct from  that  we  studied  previously  in  Illinois  (111.  Agr.  Sta. 
Bull.  29:273-300.  1893.)  since  here  we  never  found  the  III 
or  Gymnoconia  stage  associated  with  it.  In  fact,  so  far  as 
we  know,  this  stage  had  not  been  reported  from  Connecticut. 
The  past  three  seasons  (1917,  '18,  '19)  in  the  light  of  Kunkel's 
investigations  and  with  help  of  our  assistant  Dr.  McCormick, 
we  have  tested  the  germination  of  the  I  stage  obtained  from 
numerous  specimens  on  different  hosts  from  various  localities 
in  the  state.  As  a  result  of  these  germination  tests  we  have  found 
that  both  the  long  and  the  short  cycled  forms  occur  in  this  state. 
The  classification  of  these  collections  according  to  their  germina- 
tion as  given  under  the  different  hosts  (Gray's  6th  edition)  is 
as  follows : 

Puccinia  inter stitialis  (Schl.)  Lag.  Long  cycled  form.  On 
Rubus  hispidus  (wild)  2  tests;  Rubus  occidentalis  (cult.)  2  tests; 
Rubus  strigosus  (cult.)  2  tests;  Rubus  villosus  (wild)  1  test; 
Rubus  sp.   (wild  raspberry)   2  tests,   (cult,  raspberry)    1  test. 

Caeoma  nitens  Schw.     Short  cycled  form.     On  Rubus  cana- 


DISEASES    OF    RASPBERRY.  47 x 

densis  (wild)  19  tests;  Rubus  hispidus  (wild)  1  test;  Rubus 
villosus  (cult.)  2  tests,  (wild)  5  tests;  Rubus  sp.  (wild  rasp- 
berry), 1  test. 

From  the  above  it  will  be  seen  that  out  of  thirty-eight  tests  only 
ten  of  them  were  of  the  long  cycled  form,  and  with  seven  of  these 
we  were  able  later  in  the  season  to  go  back  to  the  same  vicinity 
and  collect  the  III  stage  on  the  same  hosts  and  even  on  the  same 
individuals  where  known !  In  three  cases  we  were  not  able 
later  to  look  for  the  III  stage.  At  first  we  got  the  impression 
that  the  short  cycled  form  only  occurred  here  on  blackberries 
and  dewberries  and  the  long  cycled  only  on  raspberries.  While 
this  seems  to  be  generally  true  for  this  state,  later  results  show 
that  no  host  is  infected  by  only  one  form,  unless  it  is  Rubus 
canadensis,  the  wild  dewberry.  From  this  host  all  of  the  19 
tests  have  yielded  the  short  cycled  form,  and  we  have  never 
collected  the  III  stage  of  Gymnoconia  on  it.  But  even  here 
some  of  the  spores  in  the  same  cultures  with  the  short  cycled 
have  given  germ  tubes  that  were  of  the  long  cycled  type  as 
far  as  determined  without  special  staining.  That  Rubus  cana- 
densis is  a  possible  long  cycled  host  in  this  state  we  have  further 
proved  by  an  inoculation  experiment  as  follows :  Long  cycled 
spores  of  the  I  stage  from  Rubus  hispidus  from  Norfolk  were 
placed  June  nth  in  Petrie  dishes  on  a  leaf  of  Rubus  canadensis. 
On  July  14th  there  had  developed  on  this  leaf  numerous  mature 
sori  of  the  III  stage  of  Gymnoconia  inter stitialis  (See  Plate 
LII,  b).  On  the  same  date  I  spores  of  the  short  cycled  form 
on  Rubus  canadensis  from  Norfolk,  collected  at  the  same  time, 
placed  on  a  leaf  of  R.  canadensis  in  a  Petrie  dish  failed  to  pro- 
duce any  infection  whatever !  This  we  had  tried  before  without 
results  and  also  several  times  in  the  past  have  tried  to  infect 
plants  in  crocks  of  Rubus  canadensis  with  spores  from  the  same 
host  and  have  never  succeeded. 

Our  failures  to  secure  infection  of  Rubus  sps.  with  the  short 
cycled  form  and  the  fact  that  it  produces  sporidia  that  might 
easily  be  blown  some  distance  has  led  us  to  consider  if  it  might 
not  be  a  heteroecious  rust  having  other  stages  {Melampsora  for 
example)  on  entirely  different  hosts.  So  for  some  years  past 
we  have  been  trying  to  inoculate  various  hosts  but  without  re- 
sults.    The  hosts  and  years  of  inoculation  are  as  follows:     In 


472         CONNECTICUT    EXPERIMENT   STATION    BULLETIN    222. 

1914,  on  Populus  deltoides;  in  1916,  on  Populus  deltoides,  P. 
grandidentata,  P.  tremuloides,  P.  alba?,  Salix  sp. ;  in  1917,  on 
Salix  sps.  (four)  ;  in  1918,  on  Populus  sp. ;  in  1919,  on  P.  deltoides, 
P '.  grandidentata,  P.  tremuloides,  Betula  populifolia,  B.  lenta, 
Salix  sps.  (two). 

With  Atkinson's  theory  that  the  same  individual  host  in  this 
locality  may  one  year  produce  the  short  cycled  form  and  another 
year  the  long  cycled,  according  as  the  weather  at  the  time  is  warm 
or  cold,  we  cannot  agree.  We  have  in  several  cases  tested  the 
spores  from  the  same  definite  locality  during  different  years,  and 
they  have-always  given  the  same  result.  We  have  collected  the 
III  stage  for  three  years  on  the  same  plants  of  Rubus  occidentalis 
at  Birdsey's,  East  Meriden,  and  the  tests  of  the  I  stage  there  have 
always  been  long  cycled.  Furthermore  we  tried  the  germination 
of  both  long  and  short  cycled  spores  several  times  at  ordinary  room 
temperature,  and  then  tried  their  germination  in  iced  water  and 
got  no  different  results.  If  temperature  determines  the  type 
of  germination  why  should  collections  made  in  the  same  vicinity 
on  the  same  date  but  from  different  hosts  give  different 
types  of  germination?  Also  why  in  our  higher  room  tempera- 
tures did  we  get  both  types  of  germination?  We  are  inclined 
to  interpret  Atkinson's  successful  infection  in  1917,  where  with  so- 
called  short  cycled  spores  he  produced  the  III  stage  on  plants 
kept  iced  under  bell  jars  as,  due  first,  to  the  fact  that  he  had 
favorable  conditions  for  infection,  and,  second,  to  the  probability 
that  a  few  of  the  spores  used  normally  produced  germ  tubes 
(long  cycle),  instead  of  sporidia  (short  cycled)  as  did  the 
majority  (just. as  we  have  occasionally  found  to  be  the  case  in 
our  cultures  irom  this  host,  as  already  mentioned)  and  it  was  the 
former  only  that  produced  the  infection.  In  other  words  we 
believe  that  the  short  cycled  form  with  its  sporidia  does  not 
infect  the  mature  leaves  bat  secures  infection  through  the  very) 
young  perennial  parts  as  is  apparently  the  case  with  the  sporidia 
of  the  III  stage.  This  delays  the  appearance  of  the  infection 
until  the  next  year  when  the  I  stage  is  produced  from  the 
perennial  .mycelium.  This  would  account  for  our  failure  to 
infect  Rubus  through  the  leaves  with  the  short  cycled  form,  and 
would  explain  the  successful  infections  with  this  stage  reported 
by  both  Atkinson  and  Kunkel  the  year  after  their  inoculations 
were  made. 


DISEASES    OF    RASPBERRY.  473 

From  the  observations  of  our  own  and  those  of  the  various 
other  investigators  we  therefore  come  to  the  following  con- 
clusions. 

(i)  There  are  two  forms  (not  species  or  genera)  of  the 
formerly  so-called  Caeoma  nitens  in  this  country.  One  of  these 
produces  only  one  spore  stage,  aecial  spores,  and  can  be  termed 
Caeoma  nitens  Schw.,  and  the  other  produces  both  aecial  and 
telial  spores  and  can  be  termed  Gymnoconia  inter  stitialis 
(Schl.)  Lag. 

(2)  Caeoma  nitens  through  the  fusion  of  the  two  nuclei  in  the 
aecial  spores,  for  some  still  unknown  reason,  has  become  a 
short  cycled  form  and  cuts  out  the  telial  stage  entirely,  but  on 
germinating  functions  as  such,  as  shown  by  development  of  a 
promycelium  and  sporidia.  Gymnoconia  inter  stitialis  has  aecial 
spores  whose  two  nuclei  do  not  fuse  and  so  give  rise  to  the 
ordinary  germ  tube  and  eventually  to  a  mycelium  with  two 
nuclei  to  a  cell. 

(3)  Infection  from  the  aecial  spores  of  Gymnoconia  inter- 
stitialis  takes  place  only  through  the  stomates  of  the  leaves  and 
the  telial  stage  results  from  this.  Infection  from  both  the 
aecial  spores  of  Caeoma  nitens  and  the  telial  spores  of  Gymno- 
conia inter  stitialis  takes  place  only  by  the  penetration  of  the 
germinating  sporidia  through  very  young  tissue,  usually  that  of 
the  underground  shoots,  and  this  results  in  a  perennial  mycelium 
that  the  next  season  gives  rise  to  the  aecial  stage  in  the  leaves. 

(4)  Caeoma  nitens  is  largely  confined  to  a  region  south  of 
Connecticut,  and  Gymnoconia  inter  stitialis  largely  to  the  region 
north  of  this  state,  but  in  the  intermediary  region  both  forms 
may  occur  more  or  less  commonly. 

(5)  In  this  intermediary  region  it  is  not  impossible  that  the 
forms  are  not  so  definitely  fixed  but  that  occasionally  on  the 
same  host  both  types  of  germination  of  the  aecial  spores  appear  ; 
or  possibly  the  same  individual  host  occasionally  becomes  in- 
fected with  both  forms  and  both  types  of  aecial  spores  are  there- 
fore produced  on  it.  .  .  •  • 

(6)  However,  conclusion  (5)  does  not  mean  that  once  the 
aecial  spores  on  an  individual  plant,  or  any  plant  infected  from 
these,  show  only  the  short  or  the  long  cycled  type  of  germination 
that  they  can  be  changed  to  the  other  type  by  differences  in 
weather  conditions  during  that  or  any  other  season. 


474         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

Romaine,  Lactuca  sativa  var.  Romana. 
Chlorosis.  In  a  private  garden  in  the  fall  of  1916  at  Middle- 
bury,  we  saw  an  occasional  plant  of  Romaine  or  Cos  lettuce  in 
which  the  leaves  showed  a  yellow  mottling  and  crinkling.  This, 
while  indicating  an  unhealthy  condition  of  the  plant,  was  no 
disadvantage  so  far  as  the  edibility  of  the  plant  was  concerned, 
as   such  plants  were   probably   less   bitter   in   taste   due   to   less 

chlorophyll. 

Rose,  Rosa  sps. 

Powdery  Mildew,  Sphaerotheca  pannosa  (Wallr.)  Lev.  In 
July,  1919,  specimens  of  Dorothy  Perkins  roses  were  brought 
to  the  Station  from  New  Haven  by  their  owner  to  learn  what 
caused  their  failure  to  open  properly.  Many  that  did  open  made 
inferior  blossoms  that  frequently  died  prematurely.  An  exam- 
ination showed  that  the  hips  were  covered,  in  part  or  entirely, 
with  a  thick  whitish  felt  of  the  above  fungus.  This  was  made 
up  of  mycelial  threads  with  few  conidiophores,  and  doing  little 
or  no  injury.  On  the  inside,  however,  a  less  conspicuous  my- 
celial growth,  with  plenty  of  conidia,  was  the  cause  of  the  injury 
to  the  petals,  that  prevented  their  proper  maturity,  etc.  In  the 
writer's  garden  the  same  trouble  developed  similarly  but  with 
the  perithecia,  deeply  imbedded  in  the  felty  mat,  finally  appear- 
ing. The  Dorothy  Perkins  was  injured  more  than  the  Crimson 
Rambler.  We  have  reported  this  fungus  before  but  not  on 
blossoms  causing  injury  of  this  nature. 

Fasciation.  This  specimen  was  found  in  April,  1918,  by  G. 
A.  Stack  in  a  yard  in  Westville.  The  stem  as  it  started  from 
the  ground  was  about  a  third  of  an  inch  in  diameter  and  only 
slightly  flattened.  It  gradually  flattened  toward  the  top,  which 
was  broken  off,  until  it  was  an  inch  and  a  half  wide.  The 
fasciation  seemed  to  run  off  from  one  side  since,  for  the  entire 
length,  one  side  was  slightly  marked  by  its  thicker  more  rounded 
character  until  near  the  end  where  it  was  entirely  separated  as 
a  distinct  naturally  rounded  stem  about  a  quarter  of  an  inch  in 
diameter.  This  extended  for  less  than  a  foot  but  had  been 
cut  off  here  as  had  the  flattened  portion  so  the  nature  of  the  tips 
could  not  be  determined.  Stewart  (N.  Y.  Agr.  Exp.  Sta.  Bull. 
328:392.  1910.)  describes  and  figures  somewhat  similar  fas- 
ciations  of  rose  which  are  said  to  be  not  uncommon.  See 
Asparagus  in  this  Report  for  other  cases. 


DISEASES   OF   SPINACH,    ETC.  475 

Rye,  Secale  cereale. 
Scab,  Gibber ella  Saubinetii  (Mont.)  Sacc.  The  conidial  stage 
of  this  fungus,  which  until  recently  has  been  known  as  Fusarium 
culmorum,  was  found  in  this  state  for  the  first  time  in  two  rye 
fields  at  Yalesville,  in  1918.  It  occurs  in  the  heads  causing  all 
or  a  part  of  the  spikelets  to  die  prematurely,  the  fungus  show- 
ing at  the  base  of  these  as  a  pinkish  growth.  While  the  disease 
is  bad  in  the  middle  west,  it  does  not  seem  to  be  at  all  common 
or  serious  here  in  Connecticut.  The  same  thing  occurs  on 
wheat,  q.  v. 

Spinach,  Spinacia  oleracea. 

Dampening  Off,  Pythium  deBaryanum  Hess.  Mr.  H.  D. 
Johnson  of  Highwood  called  the  writer's  attention,  late  in  Sep- 
tember, 1919,  to  a  young  spinach  field  of  his  that  had  been  seri- 
ously injured  by  the  plants  dampening  off  irregularly  in  the  rows, 
making  a  very  uneven  stand.  The  plants  had  come  through  the 
ground  during  a  rather  wet  period  which  proved  to  be  especially 
favorable  for  the  development  of  the  disease  since  a  field  planted 
a  short  time  later  did  not  develop  the  trouble.  The  seedlings 
an  inch  or  so  high  dropped  over,  the  trouble  first  showing  as  a 
blackish  or  brownish  softening  of  the  tissue  just  below  or  above 
ground.  After  falling  over  they  wither  up  in  dry  weather  and 
soon  disappear.  Mr.  Johnson  had  never  been  troubled  before  in 
this  way  and  it  was  the  first  time  we  had  seen  dampening  off  in  a 
spinach  field,  although  we  had  seen  the  disease  on  other  seedlings 
in  seed  beds  and  greenhouses. 

An  examination  of  the  tissues  revealed  the  presence  of  an 
abundant,  guttulate,  non-septate  mycelium  of  the  phycomycetous 
type,  but  no  very  evident  spore  stage,  except  possibly  temporary 
sporangia.  After  the  seedlings  were  left  in  water  for  a  few  days 
a  rather  luxuriant  growth  of  mycelium  developed  around  them 
and  in  this  appeared  the  temporary  sporangia,  and  finally  definite 
oogonia  and  oospores.  These  agreed  very  well  in  size  and  ap- 
pearance with  those  grown  in  artificial  cultures  recently  received 
from  the  Department  of  Agriculture  at  Washington.     Plate  LVI. 

The  oogonia  varied  from  18-27^,  chiefly  20-25/x,  and  the  oos- 
pores from  15-21^,  chiefly  16-18^.  The  oogonia  and  oospore 
walls  remain  hyaline  and  the  latter  are  not  very  thick,  usually 
2-2. 5/x.      It    seems    characteristic    of    this    fungus    to    produce 


476         CONNECTICUT   EXPERIMENT    STATION    BULLETIN    222. 

oogonia  much  more  readily  in  a  liquid  than  in  a  dry  medium,  so 
that  a  portion  of  our  agar  cultures  transferred  to  water  in  a 
Petrie  dish  developed  them  much  more  abundantly  than  before. 
On  oat  agar  the  fungus  rapidly  develops  a  very  prominent, 
fluffy,  aerial,  white  growth,  with  some  oogonia  and  temporary 
sporangia.  The  temporary  sporangia  look  much  like  unfertilized 
oogonia.  On  roots  of  peas  and  corn  (q.  v.)  this  same  year  we 
found  different  specimens  with  larger  oospores  that  we  have 
placed  under  Phytophthora  cactorum. 

Spruce,  Norway,  Picea  excelsa. 
Felt  Fungus,  Coniophora  byssoidea  (Pers.)  Fr.  Mr.  Walden 
found  this  fungus  on  young  plants  of  Norway  spruce  imported 
from  France  in  1918.  In  the  packing  cases  it  had  developed  a 
very  conspicuous  felty  growth  of  the  tawny  mycelium  over  the 
individual  stems  running  up  onto  them  from  the  soil.  Whether 
it  caused  any  harm  was  uncertain  but  probably  it  was  develop- 
ing merely  as  a  saprophyte  under  these  favorable  conditions. 
Dr.  Burt  confirmed  our  determination  of  the  species. 

Sumach,  Rhus  glabra. 
Fasciation.  Near  the  Station  grounds  a  stem  of  the  common 
sumach  was  found  in  19 19  that  from  the  ground  up  gradually 
flattened  out  until  the  flattened  part  was  twice  the  normal  width 
of  the  stalk  and  much  thinner.  The  end  was  bifurcated  into 
short  tips  curved  in  opposite  directions.  Brannon  (Bot.  Gaz. 
58:518-26.  1914.)  describes  a  fasciation  of  cottonwood  and 
willows  on  young  sprouts  from  stumps  of  trees  cut  down  the 
year  before,  and  discusses  the  causes  of  this  and  other  cases 
of  fasciation.     See  Asparagus  in  this  Report. 

Sweet  Pea,  Lathyrus  odoratus. 
Root  Rot,  Phytophthora  cactorum  (Cohn  &  Leb.)  Schroet. 
In  our  Report  for  1907,  p.  359,  under  Sweet  Pea  we  mentioned 
Pythium  and  Rhizoctonia  as  causes  of  dampening  off.  The 
specimens  discussed  there  were  brought  to  us  in  July,  1907,  by 
Mr.  Walden  of  this  Station  from  his  garden.  A  re-examination 
of  them  shows  that  the  so-called  Pythium,  whose  oogonia  with 
oospores  were  present  in  the  cortical  tissues  of  the  roots,  is  the 
same  thing  that  in  the  present  Report  we  have  discussed  under 


DISEASES   OF   TOBACCO,    ETC.  477 

peas  and  called  Phytophthora  cactorum.  The  oospores  from  the 
sweet  pea  are  figured  in  Plate  LVI,  3,  and  can  be  compared  with 
those  found  on  the  other  hosts  reported  here. 

Root  Rot,  Fusarium  sp.  As  well  as  the  garden  pea,  the  Sweet 
Pea  has  similar  rots  due  to  Rhizoctonia,  Phytophthora  and 
Fusarium,  and  the  effect  produced  by  all  three  is  much  the  same, 
in  that  the  half-grown  plants  turn  yellow,  wilt  and  dry  up  due 
to  the  rotting  of  the  roots  and  base  of  the  stem.  The  Fusarium 
specimens  reported  here  were  sent  from  the  Stoeckel  estate  at 
Norfolk,  in  June,  1918.  The  fungus  is  probably  the  same  species 
that  causes  more  or  less  trouble  in  greenhouses  on  cuttings,  etc. 

Sycamore,  Plat  anus  occidentalis. 
Electrical  Injury.  Trees  near  trolley  lines  are  sometimes  ap- 
parently killed  by  leaks  in  the  feed  wires.  In  the  summer  of 
1918,  a  sycamore  tree  along  the  trolley  line  in  Centerville  showed 
such  injury  on  a  single  branch  which  had  come  in  contact  with 
the  feed  wire  where  the  insulation  was  worn  off,  A  decided 
burn  showed  on  the  under  side  of  the  branch,  and  the  leaves  had 
all  died.  The  insulation  on  the  feed  wire  was  evidently  quite 
poor  and  for  a  distance  of  half  a  mile  small  twigs  here  and  there 
on  the  street  trees  could  be  seen  that  had  recently  been  killed, 
apparently  when  the  wet  leaves  came  in  contact  with  the  poorly 
protected  wire. 

Tobacco,  Nicotiana  Tabacum. 

Besides  the  troubles  described  here  we  have  run  across  several 
more,  chiefly  of  the  leaf  spotting  type,  but  because  of  their 
obscure  nature  we  have  omitted  consideration  of  them  for  the 
present.  All  of  the  troubles  discussed,  except  the  first,  are  of 
a  non-parasitic  nature. 

Bacterial  Soft  Rot,  Bacillus  carotovorus  Jones.  Plate 
LIII,  b.  The  only  place  where  we  have  seen  this  trouble  was  on 
W.  J.  Reeves'  tobacco  at  Windsorville.  We  first  saw  it  there  with 
Johnson  of  the  Wisconsin  Station,  in  July,  19 18,  and  found  it 
there  again  in  19 19.  Only  a  few  plants  in  the  field  showed  the 
trouble  but  these  were  mostly  in  the  same  row  or  near  each 
other.  The  disease  starts  at  the  lower  end  of  the  plant,  rotting 
out  the  pith  so  that  the  stem  can  easily  be  crushed  with  slight 
pressure  though  the  outside  may  seem  nearly  normal.     The  rot 


478         CONNECTICUT    EXPERIMENT   STATION    BULLETIN    222. 

eventually  reaches  and  invades  the  veins  and  tissues  of  the  leaves 
when  they  drop  down  and  finally  die.  Johnson  (Wise.  Agr.  Exp. 
Sta.  Bull.  237:27.  1914.)  has  briefly  mentioned  this  trouble 
under  the  designation  "hollow  stalk."  He  claims  it  can  be 
produced  by  inoculation  and  we  succeeded  in  so  doing  by  cutting 
into  healthy  plants  and  inserting  diseased  tissue.  Not  having 
worked  on  the  trouble  from  a  bacterial  standpoint,  we  merely 
assume  that  it  is  not  different  from  the  ordinary  soft  rot  troubles 
found  here  on  a  variety  of  plants. 

Fire  Injury.  Occasional  tobacco  plants  under  tents  are  more 
or  less  injured  by  the  cloth  of  the  tents  catching  fire  and  the 
burning  fragments  falling  down  on  the  leaves.  Sparks  from 
locomotives,  cigarettes  and  incendiarism  are  causes  of  such  fires. 
Some  growers  have  supplied  watchers  to  prevent  them.  See 
Lightning  Injury. 

Frost  Mottling.  Plate  LIII,  a.  A  curious  case  of  frost  injury 
to  young  tobacco  plants  was  called  to  our  attention  the  latter 
part  of  July,  1918,  by  Mr.  Beinhart,  the  Government  tobacco 
expert,  at  the  tobacco  farm  of  Mr.  Eastwood  in  Somers.  The 
owner  noticed  the  trouble  about  the  first  of  July,  shortly  after 
there  had  been  an  unusually  late  frost  in  that  neighborhood. 
During  the  two  weeks  that  had  elapsed  since  first  seen  by  Bein- 
hart and  then  by  both  of  us,  the  injury  had  become  less  con- 
spicuous according  to  him.  At  the  latter  date  the  plants  still 
showed  considerable  spotting  and  some  irregularity  of  leaves, 
especially  of  the  lower  older  ones.  The  spotting  was  due  to  the 
chlorophyll  being  killed  in  spots  that  were  now  whitish  or  white 
and  so  in  strong  contrast  with  the  rest  of  the  normally  green 
tissues.  Sometimes  these  white  spots  were  large  areas  and  some- 
times small  specks  of  a  mottled  arrangement,  as  shown  by  the 
two  leaves  photographed.  Such  injury  follows  light  frosts,  with 
possibly  moisture  on  the  leaves  where  their  tissues  are  injured. 

Hail  Injury.  Plate  LIV.  On  August  4,  19 17,  we  visited, 
with  Beinhart  and  Johnson  of  the  Dept.  of  Agriculture,  the  re- 
gion in  East  Sufrield  where  a  storm  on  Aug.  2d  had  caused 
injury  to  the  tobacco.  This  storm  was  rather  local,  doing  great 
injury  to  some  fields,  while  other  fields  near  by  suffered  little. 
A  good  many  large  trees  or  their  branches  were  blown  down 
by  the  high  wind.     Tobacco  in  the  open  was  more  or  less  blown 


INJURIES    TO    TOBACCO.  479 

over  and  had  to  be  propped  up  again.  The  greatest  injury, 
however,  was  from  hail,  which  in  a  streak  through  the  region 
inflicted  great  damage  to  the  tobacco  in  the  open,  numerous 
fields  of  which  were  largely  or  entirely  ruined;  it  also  caused 
damage  to  the  tobacco  under  tents  in  some  cases.  This  latter 
damage  occurred  where  the  wind  was  strong  enough  to  carry 
the  cloth  from  the  tents.  We  saw  a  tent  of  ten  acres  where  the 
wind  had  whipped  the  cloth  to  pieces,  bent  and  blew  over  much 
of  the  tobacco,  as  shown  in  the  photograph  taken  by  Johnson, 
while  the  hail  entirely  ruined  what  was  not  injured  by  the  wind. 
The  hail  injury  was  very  marked  on  the  stems,  showing  white 
irregular  spots  where  the  stones  struck.  See  photo.  These  spots 
were  entirely  on  the  side  of  the  stem  from  which  the  storm  came. 
The  leaves  were  largely  shredded  from  the  stem  or  beaten  off 
on  the  ground  and  cut  in  irregular  shapes.  The  damage  caused 
to  this  one  tent  alone  was  probably  five  or  six  thousand  dollars. 
We  have  seen  tents  where  half  a  ton  of  hail  stones  tore  down 
the  cloth  and  were  piled  on  the  ground  so  that  some  of  them 
remained  there  for  twenty-four  hours  afterwards  in  warm 
weather. 

Lightning  Injury.  Plate  LV,  a.  Lightning  may  cause  injury 
to  tobacco  in  two  ways.  First,  it  may  strike  the  field  and  pro- 
duce injury  in  circular  spots  for  a  short  distance  around  where 
it  struck.  This  is  apt  to  occur  when  the  tobacco  is  young,  the 
electricity  following  the  moist  earth  comes  in  contact  with  the 
stems  where  it  entirely  kills  the  plant,  or  produces  cankers  up 
the  stem  and  injury  to  the  petioles.  It  also  usually  produces 
a  permanent  curling  or  a  wilting  of  the  leaves,  as  shown  in  the 
photograph.  Some  growers  think  that  tobacco  does  not  do  well 
in  after  years  on  these  spots.  In  one  of  our  Reports  we  men- 
tioned such  injury,  investigated  by  Stoddard,  and  in  1916  Bein- 
hart  showed  us  another  field  where  similar  injury  had  occurred. 
He  also  told  of  other  cases  which  he  had  seen. 

The  second  kind  of  injury  which  may  be  produced  by  lightning 
is  where  it  strikes  the  tents  running  along  the  wires  supporting 
the  cloth,  setting  the  latter  on  fire.  The  heat  from  the  burning 
cloth,  or  more  especially  where  the  flaming  particles  fall  on  the 
tobacco  beneath,  may  cause  considerable  injury.  Some  tent  fields 
are  protected  by  insurance  against  fire  injury.     When  fire  occurs 


480         CONNECTICUT    EXPERIMENT    STATION    BULLETIN    222. 

from  lightning  or  other  causes,  the  men,  as  soon  as  the  fire  is 
discovered,  try  to  limit  its  spread  by  cutting  through  the  cloth 
with  corn  knives.  We  saw  a  field  at  Scantic,  near  Bloomfield, 
which  had  been  struck  by  lightning  and  injury  caused  to  the 
plants  under  the  small  portion  of  the  tent  burned  over.  These 
plants  were  not  entirely  killed  but  showed  brown  dead  spots  on 
the  leaves  where  the  heat  had  been  most  intense,  or  the  naming 
material  had  touched  them. 

Potash  Hunger.  During  1919  we  had  called  to  our  attention 
several  fields  where  tobacco  was  doing  poorly  for  no  apparent 
cause.  The  leaves  often  were  yellowed  and  finally  spotted  and 
the  plants  undersized.  So  far  as  we  could  determine  the  trouble 
seemed  to  be  a  fertilizer  difficulty  due  to  insufficiency  of  potash, 
of  which  the  tobacco  plant  is  a  strong  user.  We  know  too 
little  of  the  trouble,  however,  to  speak  positively. 

Red  Root-Rot.  There  were  also  fields  or  parts  of  fields,  both 
under  tent  and  in  the  open,  that  in  1919  did  poorly,  evidently 
because  of  a  reddish  rotting  of  the  roots.  This  trouble  did  not 
seem  to  be  caused  by  fungi.  Whether  or  not  the  fertilizers 
used  then  or  in  the  past  had  anything  to  do  with  the  trouble 
is  as  yet  undetermined,  but  it  appeared  to  be  more  a  trouble  of 
that  kind  than  of  one  caused  by  fungi. 

Tulips,  Tulipa  sp. 

White  Spot.  Plate  LV,  b.  In  May,  191 9,  there  was  called 
to  our  attention  a  curious  trouble  of  tulips  of  the  Darwin  type 
at  the  Hammer  estate  at  Branford.  Each  year  the  trouble  was 
said  to  appear  so  that  because  of  it  the  growing  of  tulips  was 
being  abandoned.  Tulips  that  were  picked  early  and  taken  into 
the  house  did  not  develop  the  injury.  This  showed  as  numerous 
small,  elliptical,  white  spots  standing  out  in  strong  contrast  to 
the  variously  colored  tissues  of  the  petals.  At  first  the  spots  were 
greyish  or  blackish  but  finally  became  white  with  the  collapsing 
of  the  tissues.  The  trouble  occurred  to  a  much  less  extent  on 
the  leaves-. 

Jones  and  Miller  (Phytopath.  9:475-60.  1919.)  have  recently 
described  a  somewhat  similar  injury  on  the  leaves  of  tulips, 
which  they  call  frost  necrosis.  We  were  at  a  loss  to  account  for 
the  injury  at  Branford,  but  it  is  possibly  a  frost  injury,  since 


DISEASES    OF    WHEAT,    ETC.  40 1 

there  were  late  frosts  that  year  that  did  considerable  harm  to 
other  vegetation.  This  would  scarcely  explain,  however,  its 
presence  each  year.  Before  seeing  the  Jones  article  we  had  about 
concluded  that  this  trouble  was  due  to  smoke  injury  from 
a  nearby  steel  reducer.  It  was  only  rarely,  but  at  this  time  of 
the  year,  that  the  smoke  was  carried  over  the  tulip  beds. 

Turnip,  Brassica  sps. 
Turnip  Aphids  killed  by  Empusa  Aphidis  Hoffm.  In  the  sum- 
mer of  1916,  lice,  Aphis  pseudobrassicae,  were  very  prevalent  on 
both  white  and  yellow  turnips,  causing  a  partial  failure  of  the 
crop.  After  most  of  the  harm  was  done  to  the  turnips,  this  fungus 
got  started  and  killed  off  millions  of  these  lice.  Collections  were 
made  in  September  in  Mt.  Carmel,  New  Haven  and  Westville 
where  practically  all  of  the  lice  on  the  leaves  were  killed.  The 
fungus  is  similar  to  the  species  that  kills  house  flies  and  the  brown 
tail  moth  larvae. 

Umbrella  Tree,  Magnolia  tripetala. 
Chlorosis.  In  May,  1916,  we  received  from  Southport  par- 
tially developed  leaves  of  the  umbrella  tree  showing  a  very  marked 
yellow-green  mottling  over  the  whole  surface,  resembling 
mosaic  of  tobacco.  As  the  letter  stated  that  the  bark  was  dead 
in  places  and  the  tree  had  been  ailing  since  the  previous  August, 
it  seemed  certain  that  it  had  been  injured  in  some  way,  prob- 
ably winter  injury  as  it  is  a  little  out  of  its  range  so  far  north, 
and  that  the  mottling  of  the  leaves  was  the  result  of  very  poor 
nutrition  on  this  account. 

Wheat,  Triticum  vulgar e. 

Glume  Blotch,  Septoria  sp.  We  collected  this  fungus  once 
or  twice  in  our  disease  survey  work  in  1918  as  a  very  incon- 
spicuous parasite  on  the  glumes  and  leaves  of  wheat. 

Powdery  Mildew,  Erysiphe  graminis  D.  C.  A  little  of  this 
mildew  was  found  in  both  1918  and  1919  in  wheat  fields.  It  was 
too  inconspicuous  to  cause  any  damage.  On  rye  and  barley, 
however,  we  have  found  it  causing  much  more  injury  and  mak- 
ing a  more  conspicuous  growth. 

Scab,  Gibberella  Saubinetii  (Mont.)  Sacc.  Johnson  and 
Haskell  (U.  S.  Dep.  Agr.  PI.  Dis.  Surv.  Bull.  No.  8,  pp.  21-26. 


482         CONNECTICUT   EXPERIMENT    STATION   BULLETIN    222. 

1919.)  now  give  this  Fusarium  fungus  the  above  name  and 
report  it  very  serious  in  the  upper  Mississippi  valley  and  east- 
ward, in  1919.  We  found  it  first  in  Connecticut  in  1917,  and 
collected  it  again  in  1918,  but  as  on  rye,  q.  v.,  it  seemed  to  cause 
little  damage  in  this  state. 

Stinking  Smut,  Tilletia  foetens  (B.  &  C.)  Trel.  We  also 
found  this  smut  very  sparingly  in  the  grain  of  wheat  in  191 8. 
While  very  serious  in  the  west,  it  is  a  rare  fungus  here  in  Con- 
necticut, this  being  our  first  collection  though  we  had  reported 
it  before  in  cattle  feeds. 

Willow,  Salix  sp. 
Powdery    Mildew,    Uncinula   salicis    (D.    C.)    Wint.     This 
powdery  mildew  occurs  more  or  less   commonly  on  the  upper 
surface  of  the  leaves  of  certain  basket  willows  at  the  Station's 
farm  at  Mt.  Carmel. 


PLATE  XXXIII. 


a.     General  View  of  Invaded  House. 


b.     Rotten  Condition  of  Living  Room  Floor. 


c.     Luxuriant  Growth  of  Fungus  on  Underside  of  Boards,  etc. 
DRY  ROT  FUNGUS,   Merulius  lacrymans,  p.  398. 


PLATE  XXXIV. 


a.     Mold  of  Unsalted  Package  Butter,  p.  400. 


b.     Bacterial  Fruit  Spot,  p.  404. 


TROUBLES  OF  BUTTER  AND  APPLE. 


PLATE  XXXV. 


a.     Aerial  Crown  Gall,  p. 


\<  "  .  >'-'£;':: 


b.     Malformed  Twigs,  p.  409. 


c.     Rust  causing  Swellings  in  Ash  Twigs,  p.  414. 
TROUBLES  OF  APPLE  AND  ASH. 


PLATE  XXXVI. 


:m 


& 


a.     Fasciation,  p.  415. 


b.     Black  Leg  of  Cabbage,  p.  420. 


c.     Bacterial  Wilt  of  Beans,  p.  417- 
TROUBLES  OF  ASPARAGUS,  BEANS,  CABBAGE. 


PLATE  XXXVII. 


a.     Soft  Rot  of  Chinese  Cabbage,  p.  422. 


b.     Healthy  and  Crinkled  Celery  Leaves,  p.  424. 


TROUBLES  OF  CHINESE  CABBAGE  AND  CELERY. 


PLATE  XXXVIII. 


a.     Pellucid  Spot  Disease  of  Corn,  p.  430. 


♦"-aau****'-'- 


b.     Connate  Fomes  of  Hickory,  p.  440. 


c.     Witches'  Broom  of  Hickory,  p.  440. 
TROUBLES  OF  CORN  AND  HICKORY. 


PLATE  XXXIX. 


a.     Anthracnose,  p.  441. 


b.     Red  Canker,  p.  442. 


c.     Club  Root,  p.  443-  d-     Sulphury  Polypore,  p.  445. 

TROUBLES  OF  HORSECHESTNUT,  KOHLRABI,  OAK. 


PLATE  XL. 


a.     Bastard  and  Normal  (central)  Onion  Blossoms. 


b.     Bulblet  Head.  c.     Double  Head. 

TROUBLES  OF  ONION,  448. 


PLATE  XLI. 


a.     Goose  Neck,  p.  448. 


b.     Elongated  Spathe,  p.  448.  c.     Hail  Injury,  p.  449. 

TROUBLES  OF  ONION. 


PLATE  XLII. 


■if :  ••*-'  * 


a.     Normal  and  Blasted  Heads,  p.  447. 


b.    White  Ring,  p.  449. 


TROUBLES  OF  ONION. 


PLATE  XLIII. 


a.     Die  Back,  p.  454. 


b.     Winter  Injured  Orchard,  p.  454. 


TROUBLES  OF  PEACH. 


PLATE  XLIV. 


a.     Downy  Mildew  Rot,  p.  454- 


b.     Lightning  Injury,  p.  458.  c-     Snow  Bend-  P-  45§- 

TROUBLES  OF  PEAR  AND  WHITE  PINE. 


PLATE  XLV. 


a.     Yellow  Spot,  p.  459. 


b.     Witches'  Broom,  p.  459. 


c.     Winter  Injury  of  Buds,  p.  458. 
TROUBLES  OF  PINES   (a.  White,  b.  Scotch,  c.  Austrian). 


PLATE  XLVI. 


a.     Witches'  Broom,  p.  459. 


b.     Intumescence,  p.  460. 
TROUBLES  OF  WHITE  PINE  AND  PLEUROMA. 


PLATE  XLVII. 


a.     European  Canker,  p.  461. 


'?   I 


b.     Aerial  Tubers,  p.  462. 
TROUBLES  OF  POPLAR  AND  POTATO. 


PLATE  XLVIII. 


... 


•■- 


i,- 


* 


Sv 


a.     Normal  and  Curly  Dwarf  Vines,  p.  463. 


b.    Hollow  Heart,  p.  463. 
TROUBLES  OF  POTATO. 


PLATE  XLIX. 


^M'y-? 


wm#  * 


**» 


a.     Leaf  Roll,  p.  464. 


b.     Net  Necrosis,  p.  465. 


TROUBLES  OF  POTATO. 


PLATE  L. 


a.     Premature  Sprouts,  p.  465. 


b.     Rootstock  Invaded-Tubers,  p.  466. 


TROUBLES  OF  POTATO. 


PLATE  LI. 


/ 


a.     Section  through  Rootstock  Invaded-Tuber. 


b.     Russeted  Tuber. 


c.     Spindle  Sprout. 


TROUBLES  OF  POTATOES,  p.  466. 


PLATE  LII. 


Wilt  of  Potato  in  Center  Row,  p.  4^7- 


b.     Ill  Stage  of  Rust,  p.  469- 
TROUBLES  OF  POTATO  AND  RUBUS. 


PLATE  LIII. 


a.     Frost  Mottling,  p.  478. 


b.     Bacterial  Soft  Rot,  p.  477. 
TROUBLES  OF  TOBACCO. 


PLATE  LIV. 


a.     Tent  and  Tobacco  Destroyed  by  Wind  and  Hail. 


b.     Showing  Laceration  and  White  Spots. 
HAIL  INJURY  OF  TOBACCO,  p.  478. 


PLATE  LV. 


a.     Lightning  Injury,  p.  479. 


b.     White  Spot,  p.  480. 
TROUBLES  OF  TOBACCO  AND  TULIP. 


r  i-,r\  x  LLi  j_,  v  j.. 


1-4,  Phytophthora  cactorum:  1,  From  Corn  Roots,  p.  428;  2,  From  Pea 
Roots,  p.  452;  3,  From  Sweet  Pea  Roots,  p.  476;  4,  In  Artificial  Cultures 
from  Pear,  p.  454.  5-8,  Pythium  deBaryanum:  5,  From  Celery  Roots, 
p.  423 ;  6,  From  Spinach  Seedlings,  p.  475 ;  7,  In  Artificial  Test  Tube 
Culture  and,  8,  in  van  Tieghem  Cell  Culture  Drying  Out,  p.  452. 
9,  Pythium  hydnosporum,  From  Grape  Berries,  p.  436. 

OOSPORES  ANJD  :Oo8oNIa[oB   PHYTOPHTHORA  AND 

PYTHIUM. 


University  of 
Connecticut 

Libraries 


